Heat resistant gloves are one of the things that can stay dirty without any repercussions, as you aren’t going to be using these gloves outside of a workshop or around a heat source. Those areas are often dirty anyway, and they will probably get dirtier before you can thoroughly clean them. Regardless, if you still want to clean your gloves and give them some proper maintenance, then you can. For gloves that are designed for the grill or the fireplace, you can either wash them in the washing machine or by hand. Washing by hand is generally safer because of the properties of the leather and cotton, but if you choose to wash in the laundry, make sure to only use hot water and laundry detergent that is free from bleach and fabric softener. If you are washing by hand, you can let the gloves soak for a while in warm water, and then attempt to scrub out any stains that you see. Or you can wipe them down with a damp washcloth. If you buy a pair of welding gloves, then they will have come with instructions on how to clean and maintain them. Always make sure to get a set of instructions or a second opinion on cleaning your gloves before you choose to do so, as you could ruin your gloves if they are cleaned the wrong way.