If you are washing with a good dish washing detergent and warm water, you are doing more than a lot of usersI know of. In reality, this is all that is needed. Once dry, follow up with an application of mineral oil and your board should last for many more years.
Additionally, you can spray the cutting surface with a 1 : 1 mixture of vinegar and water, or a mixture of 1 quart water and 1 tablespoon of Clorox or coat overnight with salt and brush off in the morning.
As Boardsmith says, Nichole, you're doing just fine. The key is to not let the board soak.
I usually stand it on edge in the sink, with the hot water running, and use a Dobie pad and dishwashing soap to wash and rinse the board. The whole procedure takes about 25 seconds---and I have never understood why people don't do it.
Sanitizing is a nice extra step, but I rarely do it. I feel that between general sanitation and the wood's natural anti-bacterial properties, I've got that covered.
You just reminded me I need to hit my Boos board with some mineral oil. I hit the Boos board with a quick scrub of hot water and dish soap, quick rinse, dry immediately. Some times I had a little ammonia to a dish cloth that has been soaked in hot water with dish soap, very diluted. Quick rinse. My synthetic board pretty much the same, and every so often a little bleach. I have had my Boos about 10 years, its in great shape, no heavy chopping.
I'm guessing your cutting board is wood, and no, I don't have a problem there.
How you sanitize your board is one thing, but my main concern is:
What is the surface of your board like?
Very light scratches/cuts?
Deeper, heavier cuts?
Rough surface, or fairly smooth?
This is the main inspection criteria health inspectors have when they look at cutting boards--the surface.
You've heard of the "Pepsi challange", now I want you to take the "Silly Putty" challange.
I'm dead serious. Get a wad of silly putty and press it into the surface of the board, remove it, and examine it.
Deeper scratches and scars will harbour food debris and residue.
Doesn't matter what type of material the board is, it HAS to be softer than the knife edge.
Wood is easy to smooth. You could go to your local woodworker or highschool wood shop and ask them to run the board through a thickness planer, this will remove about 1/16" of material, giving you brand new surface. Or you could get a card scraper or a cabinet scraper and do this by hand. Thickness planers work well for nylon boards too.
Mineral oil is about the best and the cheapest treatment for cutting boards. There are blends of beeswax and mineral oil too, but plain drugstore mineral oil is just as good