I have a couple extra crestron clw-dims1rf master dimmers and I was curious if I can use one as a slave?

Yes. It can't be physically hooked up like a slave but as long as you have power to it, it can be programmed to work another switch. We do it all the time with the EX dimmers.

We never use slaves. Easier to quote and program a system. If you have a 3 or 4 way you just connect the switch leg on the dimmer that the load goes to and cap off the switch leg on the other dimmers in the 3/4 way setup. This way when you walk into someones house to quote an infinet lighting system, all you need to do is count the total amount of switches / dimmers in the house. You don't need to spend hours figuring what is a single pole and what is a 3 / 4/ 5 way.

Yup plus the slave-capable EX dimmers are double the price plus you need the slave still so its a no brainer.

But for the OP yes you can use the older RF Infinet dimmers with no load connected and program accordingly.

Not to mention they can't be configured to look like the dimmers and don't exhibit the same feedback.

I figured as much.
Thank you, I appreciate the advice.