First of all thank you for being honest yet I found your post insulting!
Some guys like to swallow, but most don't. Rimming is a very personal subject... and even with perfect hygiene there are risks, besides is waaay more personal than kissing.
If I had a dollar for every time a guy told me "but I just showered" and he wasn't ready...
Getting loaded as in taking a load up their butts? Not everybody likes to bottom and specially BB with a client... They might do it if they're on PrEP with a handsome hookup but not with a client, it's their preference.
Maybe some clients like to be the ones getting loaded and others like to rim. Other clients only do it safe and they BB with their husbands/partners.
Not everybody wants to do what you have in mind.
I'm sure there are lots of guys who get bred by their clients but rimming is not something they would do to most men who hire.