When in trade school we had a rule that all coveralls were to be put in for cleaning daily. Due to a personal issue between a classmate and a union rep, we decided to not clean our coveralls daily, nor weekly nor monthly nor ever. I had one pair go 5 months withotu washing. They stunk of oil and grease and gas, lubricants of all varieties and they were literally BLACK top to bottom.
the union rep finally resoved his issue with our freind and all went back to daily washing again.
When with Ford, again daily cleaning clean ones everyday.
When weleding and machining for a boiler and talk company, it was weekly, but I didn't get as dirty at that job because often coveralls were covered up with other protective gear.
As for stinks, i think my all time favorte, well there's two, kinda off topic to this thread though.
1) Fish fertilizer, for lawns, into the outer sir intake vents of a car. the smell does NOT go away, ever, need a completely new vent system.
2) Taped a banana to the back of a coworkers desk drawer. After about two weeks teh fruit flies started, another week or two later and his office partner moved out into the boardroom to work, fruit flies EVEYRWHERE and what a nasty smell! :D