Question about clipping nails

[Harley2013]

I have heard though don't know how true, that if you take sandpaper cover and put them on the bottom portion of the perch, when the birds land, their feet will be on perch, but nails wrap around to the sand paper part. Has anyone ever heard of this, and does it work?

[wildbird]

I did that for mine a few years ago & it worked. I only used it on a small portion of the perch, had to trim the sand paper so their feet wouldn't be on it, & I think I taped the ends with masking tape. You have to be very careful though that they don't get caught in the tape or even in the sand paper that's not tight. Best if you can find a perch that is smooth on top & rough on sides that will fit them. Also, you could put some small rough stones on the floor near a food dish or bath. I use some lava rock too.

[MiaCarter]

I've gotten pedi-perches and coated the top with non-toxic elmer's glue to create a smooth surface for the area that touches the foot.

I've also gotten those sandpaper slip-covers for dowel perches.
Cut them in half so they only cover the bottom of the perch. Then, use elmer's glue to glue them to the perch. Wrap with cellophane while the glue dries to get a good strong bond.

Or perhaps covering with painter's tape or masking tape would be sufficient. I just try to avoid tape in bird cages as it makes me nervous.

Some require actual trimming even with these measures.
The OP mentioned spice finches and in my experience, they're one species that's just insane when it comes to nail growth!
They grow so fast and the pedi-perches and stones didn't make any difference.