How do I get my parents to stop being in control when the only thing they control is changing their pants?

I am so sorry for both you and your son. Living in an environment of smoke and stench is not only unhealthy for your father but for your son as well. Has your father been diagnosed with dementia or other mental conditions that effect his decision making? Was he always a slob or is this something new? Is your son compensated for caregiving (some parents think this gives them the right to do as they please because they are "paying your for your time.") Have you shared with him your thoughts about the NH if he doesn't cooperate? You are not using this as a punishment but, as you said, as the inevitable consequence of his bad choices.
Can anyone intervene for you? another family member, doctor, friend, whom he trusts?
Failing everything else, I think it would be a good idea for you and your son to set some boundaries (ie: Dad bathes at least once a week, changes the diaps. everyday, wears clean clothes, and allows someone to come in and steam clean all the upholstered furniture.) If he does not comply, he needs to go to a place where these things can be done for him. Do not have this conversation with him until you have the plans in place and are committed to following through on them.
Good luck...I hope you find a good resolution...at least get your son out of this disgusting situation........Lilli

Thank you Lilli, yes my dad has vascular dimentia & has had a few damaging strokes. Dad does get in the shower 1 time a week but doesn't use soap just stands in the water. My dad does not talk well because of the strokes so he stutters alot... but to make us mad he laughs at us especially when he doesn't know how to respond. No my dad was never a dirty person, this has realitively just began in the last couple of months. My son is being compensated but not much, there is a small pension & ss. They live in a log home and its 35 yrs old & starting to need upgrades that mom & dad didn't keep up with. my dad was the father figure for my son & up until recently my son was committed to staying with my dad. Today is Easter sunday and neither of them has spoken to the other one. Last week was the 4th anniversary of my moms passing. My dad doesn't remember when mom died & never talks about her?????

I appreciate your son's love for his grandfather and his willingness to stick by him (all commendable) but he is in over his head.
Your dad needs more physical and mental assistance. Please do not wait until things get much worse than they are now. Your Dad needs a memory care facility. And your son has done his share. Do not let your him take on this tremendous responsibility alone any longer. He needs to get on with his life, and by getting his grandfather appropriate care, he is actually doing the loving thing for him.
Is your father and son able to move in with you until you can get things under control and find the best placement? That way, at least there would be two of you to care for your Dad temporarily.
Good luck...never any easy answers!!

I think you hit it on the head. Its kinda like tough love, its harder on us than them. I would love to get them back to my house but he doesn't adapt to change anymore. And I have alot of stairs. Dads house is a ranch. When there are living changes he has all kind of bowel accidents whereas its usually bladder issues. I need to get him back into hospice... they were so helpful. I am calling his primary doc tomorrow at 9 when the office opens. You're so right that the loving thing to do is to get them both out of there. Thank you, Lilli! You are so right never EASY!

Assisted living facilities are a blessing! Do not use the term "Nursing Home"...use either Assisted living or Retirement living facility. Do your research - there are GREAT places and some not go great. At an assisted living facility, your father will have ALL the care that he needs, companionship, laundry, meals, snacks, entertainment, activities, the list goes on! My Mom hesitated at first about moving to an assisted living and YES, they are expensive. However, I kept tellling her about all the positive things...no housework, NO WORRIES, ALL meals prepared, no shopping, etc. All she would have to do is simply RELAX & ENJOY her life without all the worries that she had dealt with all of her life. After all....all of her money that she had saved, the sale of her house...it is HERS to use NOW..."at retirement"...
Me & my siblings kept telling her to stop worring about an inheritance for us....gosh...that money is for her.."when she needed it" which is NOW! That it would be just a great if, at her passing, she left us a million dollars or one single penny...as long as SHE is HAPPY, WELL cared for & worry free....just to simply LIVE!!!!! She loves it now! She has made so many friends, the staff are WONDERFUL, caring & so loving. She even found a "summer" romance last summer at 80 & he was 90. (He has since passed *RIP) She has moderate alzheimers now and they were both convinced they were married. Such a special time.
It is hard....PLEASE do research & read about the illness your Father has....TRUST ME....IT IS SO HARD....but remember....this man that is giving you a headache now...is NOT your father that loved and cared for you as a child....this disease is slowly robbing you of who he is/was....ENJOY EVERY single SECOND while you can....take a trip down memory lane when times get tough....there WILL be a time that he will not recognize you or even himself....and lastly .... Prayer ALWAYS helps. "This too shall pass" and "I can do all things through Christ who strengthens me"....say them over & over! God Bless you & your son.