Cleaning Rocks

[CaptnIgnit]

So I found a few rocks in my backyard (actually have a ton of lava rock pebbles) but a few of them have some dirt that is relaly compact. I already boiled them for about an hour but the dirt remains on the rocks. Is there anything I can do that will clean the rocks off besides scrubbing them for hours?

Also, I did a vinegar test but am not quite sure what I should be looking for? should I look for bubbling or foaming?

TIA

 

[MattAquaBio]

If it fizzes i believe you shouldnt use it. Also, like steel brillo pads or whatever, you could try one of those, or one of those brushes you scrub your tires with?

 

[CaptnIgnit]

ah steel pads! so obvious!

thanks

 

[coldmachineUK]

You could also just leave them to soak in water for a week or two: that will loosen dirt etc.

 

[JDogg]

make sure you use the brillo pads that DO NOT come with soap already in them...

let them soak in water a few days, and if you have a hose, you can get a nozzle that will alow you to make a high power jet and really blast them...