Well I thank you for all your suggestions.
I don't think slipping in the shower is a concern for him, as he goes to the gym 3 days a week to work out, and the other two days volunteers at a museum. In other words, he is fairly active. He has is own apartment in our house, and a walk in shower stall so he can stay upright all the time.
I think rather than the snatch and grab, when we leave for the gym today, I will just happen to be throwing in a load of clothes and "see if he has anything to go in".
The other thing he does it to wear a shirt and then instead of throwing it in the laundry basket, he will put it back on a hanger and put it away. I actually go through his closet performing a sniff test on laundry day.
I have been using Nature's Miracle on his pants to remove any residual odor after laundering. It is really hard to get that smell out, and he has a favorite pair that odor clings to really badly.
I also feel that his hygiene is a reflection on me, which I probably shouldn't, but I know if I met someone with the same issue, that I would wonder if their family were taking care of them properly.