Umm...not to be gross (or state the obvious) but you do realize you put dirty clothes in the washer now, right? Sweaty workout stuff, stinky guy clothes, undergarments...you get the idea. You may not have kids but trust me anyone with kids has put pottied on or thrown up on sheets in there at 2 a.m.
I have not bought a disposable potty pad in about 2 years.
I get my washable pads through here:
Reusable Bedpads/Underpads For Incontinence Care
Washable Bed Pads
I agree with Elaine. Use bleach and you will never smell anything (but bleach) in your washer.