Even if you have a shorter time horizon, you will forgo significant savings opportunities by cashing out your TSP. For example, if you are 45, your $20,000 will grow to $53,855 in 17 years. Keep in mind that even if you really need the money, you may be better off borrowing from your TSP account.
Here, in NYS, rubber floor mats take a real beating during the winter. I use Hi-Temp tire cleaner (amazing stuff) and a brush to scrub the rubber, a procedure very similar to yours. Dressing-wise, I apply whatever looks good at the time, though, I've been really liking Tropi-Care's White Pearl as of late.
You'll probably benefit from keeping melamine foam erasers on hand. Now on the market for a couple of years, eraserlike products that get rid of stains you thought you were stuck with for good have become a common household item. For example, Mr. Clean sells a line called Magic Erasers and Scotch-Brite offers a product called the Easy Erasing Pad. The secret behind these types of erasers is a material commonly called melamine foam. With just a little water, melamine foam can dig in and destroy stains that other products can't touch.