I have very similar steps, it is nice to have the gradual entrance into the pool and as far as I have searched, I have not found another design that provides for the removability without the compromise of uncirculated water in the tubing of the steps.. here’s what I done for the last 4-5y.
1. i scrubbed the heck out of the parts outside
2. I drilled bigger holes to clean the inside with soap and algaecide, using a little hose nozzle to get inside
3. I keep them outside the pool, hanging in my garage for fall and winter, fully drained which means turning them all sorts of directions to empty the water out
4. when it’s time to put them back in the pool I take a few tablespoons of granular bleach and drop it in the holes as the stairs are filling water. Having the bleach inside the railings and steps reduces the amount of algae that builds up in them..but
5. I also get water bugs occasionally and if I’m worried they’re in the steps, I take a funnel and dish soap and add it into the holes and it seems to do the trick.

I end up with a little smell of soap and chlorine for a day or so right by the steps but it is worth not having to wrestle with algae.

I have a salt water pool too which helps a great deal!

Byron,I have these same steps and they stink. Every year I have such an algae problem around them.I’m getting ready to open my pool and will be putting them back in as I can’t afford new steps this year. I’m thinking that I may take some algaecide and put it in the bigger holes and plug them with rubber stoppers after the stairs fill with water. I’m at my wits end trying to keep them clean and am ready to try anything at this point. If any body else has any more ideas,please help.