They can smell you are there and can smell the trap. Clean or dirty, they will smell something is different. But remember trapping is a game of numbers and odds. The odds are staked against us when it comes to disturbances and smells. Anything you can do, even if cleaner traps only increase your odds by 1%, to increases your chances will pay off in the end. You have to weigh out for yourself what’s worth it.
I trap grey fox and cats on public land. So for me, trap numbers increase my catch numbers more than scent control. So for me to change out gloves for riding around, then trap setting, then lure placement, isn’t worth it because it slows me down more than it helps me. Same with laying out a tarp to kneel on while making sets. I need to get in, make as many sets as I can, catch numbers, then move to the next area if I want numbers. I have endless amounts of land to trap with a limited season.
If I was trapping coyotes and red fox on private land where I am limited on land (which means limited on animals), it’s worth it to change gloves, use kneeling mats, and being careful to keep my trap clean. I would be trapping on limited amount of land, for animals that are very well know for digging up traps. In that example the amount of sets I should place is limited to the amount of land I have permission so taking my time for scent is more important.
Just have to look at your target species and style of trapping to determine what is best for your line.