Making new rocks safe for the aquarium

[RedFish]

I bought a bag of flat polished rocks at the dollar store.
They appear to have just been polished, no visible waxing, but it is likely that they may have been washed somewhere in the process.   

Is there a way to clean them (vinegar...) and boil them so that I could be sure they are 100% safe to use in the aquarium, or shall we just enjoy them outside of the aquarium and I will look for some flat rocks in nature once this snow is all gone.

[oenology]

I've used them before from the dollar store and didn't have any problems with them. I just rinsed them and put them in the aquarium.

[gonna_b_no_1]

I will actually admit to NOT rincing them and pitchin em in to my tank.  everyone lived! 

[RedFish]

Great!  Thanks to both of you!

[PoisonJello]

if you are worried about the rocks having something on they just boil them first (and let them cool off first before you throw them in your tank  ) any rock should be fine to use if you boil or bake them first as long as they don't have any chemicals on them (even if they had some type of chemical on them, after they are boiled they are usually safe)
Bake in oven at 400 for 35 to 40 minutes and let cool in the oven
Boil on high for about 25 minutes and let cool
oh ya if dirty wash them good first

enjoy your new rocks