I have an Oliso and wouldn't give up
I also have one of the silicon pads that I used for my old iron and it worked well. I still use it ... when I'm ironing WOF and I have the space for the Oliso on the board, I set the silicon pad on my cutting board then set the Oliso on top if it so it's off the ironing board. Even though my Oliso has the feet - I don't want it touching the cutting board even for a second so the silcon pad works.
You can use any kind of silicon pad as long as: It's large enough to cover the whole surface of the iron, and it not a solid flat pad with no raised areas. So you could get one from a kitchen store. I also have two pot holder size silicon pads (both have raised ridges) that I could also use if I butt them together.