How do you keep your kitchen sponges free of bacteria?

I don't use a dishwasher (for a variety of unrelated reasons).
What I use is:
- Warm water (simply becuase it feels better on hands)
- Costco dish detergent concentrate (whatever was on sale, Dawn or Palmolive)
- Costco curvy yellow/green scotchbrite sponges (in the multi-pack)

Each morning or evening (whenever I remember), I do the following:
a. I gently squeeze the sponge (if it's soaking wet)
b. I put it in the freezer drawer panel
c. I replace with a dry sponge (from a basket under the kitchen sink)
d. I put the old freezer sponge under the kitchen sink (in a basket)
e. Over time (as needed), I throw away & rotate with a new sponge

The concept is to let three things lessen the number of bacteria:
1. Time spent wet is never longer than a day
2. Freezer is simply one inhibitant to bacterial growth
3. Drying is just another inhibitant to bacterial growth

In the past, I tried boiling, soaking in alcohol, vinegar, and even bleach,
but most of that made the sponges fall apart, whereas freezing and drying
doesn't seem to damage the sponge in the least.

How do you keep your kitchen sponges free of bacteria?