How do I get the stale grease smell out of hot pads & potholders

I soak everything in vinegar. But that is me.

Use bleach, laundry detergent and fab softener and set washer to heavy soil. If color is more important than odor, use peroxide instead of bleach. May want to add personal cycle on to heavy soil if using peroxide.

oops add a pre-soak not personal cycle.

https://www.mnn.com/food/healthy-eating/blogs/how-to-give-your-pot-holders-a-deep-cleaning

Try rubbing baking soda into the item, it will neutralize the Oder and give the grease something to grab on to so you can remove it from the item. Next wash with dish soap to remove all of the grease and oil

I would try warm water if possible with baking soda in it. Then put some vinegar in the rinse cup not in the wash but in therinse where softener goes.

Wash with Dawn by hand and then put in a baking soda rinse and then clear water. Hope that helps

Lemon juice might do the trick. It's slightly acidic and if you boil it (or lemonade) in the pain, the scent might make you forget that nasty smell.

Or you could use denture cleaning tablets in the pots.