UV sterilizers.. Pros / Cons?

In a previous topic I stated that I was against treating rock with muriatic acid or bleach which I still am. My reasoning for this is first I have done both, the rock cured with bleach I dumped because I was not confident that the bleach could ever get completely rinsed off. Rock is porous and some of the bleach must get into the pours and I never felt that the rock ever lost the bleach smell even after rinsing for a week and air drying in the sun. Muriatic acid, first off this stuff is bad, I used a very diluted solution and the bins foamed over for hours. When I remover the rock from the solution there was a pasty white almost like clay coating to the rock. What I discovered was the acid actually erodes the calcium and makes the rock smaller and until it sets softens the outside. Some of the smaller thinner walled rock was unusable.
Some of us reefers who were from the Boston area bought large amounts of the old Marco rock. The stuff looked great and shapes and sizes were awesome and at prices between 2.00 and 2.60 a pound it was a steal. The problem was the rock was harvested from the ocean, power washed, put in a warehouse and dried. There was fauna that was in the crevices that died hence phosphate which absorbed into the rock.
I am trying lanthanum chloride on a few pieces of the Marco rock I know have high PH readings. The thing I like about lanthanum chloride is you add it to the water column and it immediately adheres to the phosphate without soaking into the rock.

I am doing both, I put one rock in a container and added the LC directly to the water and the other is in a 20 gallon tall with an over flow and a small Rubbermaid container, the overflow is draining into a 10 micron sock.

.. Looking to see what your outcome is/was BriMc