Power Commercial to Glider Commercial

I'm looking at adding a commercial glider rating this summer. Never been in a
glider, but my hunch is that it will be a good learning experience even though
I'll never fly one for hire.

So ... trying to divine the meaning of Part 61.129(f)2

"20 flights in a glider as PIC" and "5 solo flights"

But ... I can't log PIC time while getting dual instruction since I'm not rated
in the airplane. So, I'm really looking at 20 solo flights. Right?

(The only way I could see someone having 20 flights as PIC and but only 5 solo
flights would be if the person had a fairly new Private glider rating and then
took dual for the Commercial. Right?)

TIA