I just bought an LG as a hatcher for my staggered hatches, but I ran several in the same incubator this Spring. I cleaned out the incubator thoroughly after each hatch. Basically, I just very quickly emptied everything, scrubbed the incubator down, ran bleach over it, rinsed it thoroughly, dried it with a towel, and stuck it back together. The entire operation took less than 15 minutes, which is a reasonable amount of time to let the eggs hatch. I have not lost a single one to this procedure, though I have had some other problems I believe are related to the higher humidity during lockdown for the eggs that are not getting ready to hatch. They don't die during the lockdown, but have had a hard time hatching later I believe because their air cells are not developing properly.
That is why I have the LG--it's working fine as a hatcher so far, and it means the other eggs don't have to go through lockdown before their time.
But yes, I would definitely clean it out, and thoroughly. That bacteria load will eventually start killing your babies before they hatch.