I'm sorry, but I have to intervene here.
Methamphetamine has a basic nitrogen that gets protonated to form a conjugate with hydrochloric acid (HCl). The resulting crystalline mass should be titrated in aqueous solution to a pH of 4-5, or it can be gasified into a nonpolar solvent phase containing meth-base.
If the cook has over-acidified the product, it's not a big deal.
Grab a funnel and prepare a coffee filter by spraying it with acetone to pre-wet it. Place the crystals in the filter and wash them with a few cold dashes of dry acetone. That's it!
Keep the washing liquid for later crystal yieldings. It will mostly have a yellow or pink tinge. Spread the crystals out to dry and enjoy bright, white ice sticks. This time, the foil will stay sturdy and unharmed.
Got it?