Turn inside out and use them again...
I was brought up in a naval town, and there was a story going around about a sailor who caught an STD. When he visited the MO was told he should have used a condom, and he replied that he had done. Asked for an explanation, he said he'd visited a whore with a shipmate, and after his friend had fucked her, he'd turned his mate's condom inside out and used it for his fuck.
I knot them and bin them. Hate it in swinger clubs when guys just pull them off and throw them on the floor of playrooms. I've even seen them floating in jacuzzis, some people are just sluts!