There is no gentle way to go through his laundry list of missed personal care.

He has all sorts of funk going on- so you have multiple issues here.

If you want this, you are going to have to tell him the truth. Perhaps you approach it a bit more indirectly and express it as preferences like...

"Not sure if you notice, but I always make sure to shower and smell good for you...I love it when my guy smells fresh and clean too...."

But I will be honest. I think either he is incredibly lazy and shortsighted or he was completely failed at being raised to care for himself. I am not sure simple relationships will motivate this dude to make huge, meaningful changes.