Surprisingly,
the biggest breeding place for bacteria are kitchen sponges. It turns out that the absolute best way to clean your sponges is to microwave wet sponges for two minutes, or to put them in your dishwasher.
I put mine in the dishwasher weekly. My wife hates it, because they come out gorged with soapy water, but not a single microorganism survives the 55° of the dishwasher, so it’s actually very safe, if disgusting.
Here’s the link to the supporting study done by real microbiologists:
Microwave, dishwasher best for cleaning sponges
These two methods are fool-proof and FAR better than cleaning, bleach, or lemon juice.