rock with aptasia, can i kill it in one shot?

[Myka]

I use a blow torch on single rocks that are bothering me. I just blow torched one rock of mine that started growing like 5 different kinds of random algae. After blow torching I put it in a bucket of saltwater with a powerhead and heater for a couple weeks to make sure any die off doesn't cause a mini cycle in the tank. Then I test the water the rock is in for ammonia, nitrite (optional), nitrate, and phosphate. If all is 0 I put the rock back in the tank.