Fairly reliable. These typically will last about a year or better. The one I am replacing has lasted well beyond a year and was used in a 24/7 operation and heavily used as a start stop. $20 bucks seems a little high for this item though. Easily changed.
Yo Pookie, did you check to see if you could use a footswitch like the ones on a power rodder for sewer? I know they are water proof and you may be able to get one through their parts dept. Just a suggestion!