how to loosen tight curls?

I would use an impact driver. Or wrench.

Stores that sell supplies for dance generally have a large selection of tights, among other things.

they are safer...

Yes, I do. It's called the "hack". it was named that because the first ones were simply indentations cut out (Hacked) of the surface of the ice with a hatchet or an ax. It's a popular winter sport in my area, and I participated in it for a couple of decades.

In the long run it will be MUCH more cost effective (and healthy) to remove that entire tile panel, take away the wallboard and replace with fibre or concrete board, then re-do the finish with new tile and grout. -Patch repairs on this kind of thing only last a year or two. -Trust me, I re-do many ...

well yes and no.....you can use any type of stone as long as it meets the spec of the sport....but the stone said to be the best and the only stone used in olyimpic curling is made of alisite, a type of granite only found on the Ailsa Craig an island off the coast of Scotland...Kays of Scotland ...