Thanks for the comments. I've tried the credit card approach, doesn't really work as well as I'd like. I find that my fingers work best.
My #1 goal in getting back into the hobby was to have care-free maintenance. I'm not getting that with the fine sand.
And I don't want scratches. With gravel, they can be avoided. I had a bad scratch on my last tank that was caused by me wiping that tank carelessly ... it had sand.
I also ready have some large gravel/small rocks, they are just hard to see because the fine sand spit out by the mixtecos keeps burying them, plus there are not that many, and they are mostly around the big rocks.
They may not be impressing you that much now but when they are fully mature and your males are approaching 7inches they will look magnificent.
It's not about me not liking the fish. It's just about the substrate and whether I think the fish are compatible with the fine gravel or not. In retrospect I should have stuck with my original thought of not doing sand and picked compatible fish.
I just became enamored with Thorichthys (still am), and decided to go for it anyway. Actually, it's all your fault for having such beautiful fish.
Not sure what I'm going to do, won't act for at least a week. More opinions welcome.