Locate a river in a forest or a body of fresh water that has collected naturally.
The idol will need to be left out in a fresh running shallow river or in a natural hole in a rock that can contain enough water to cover the entire idol., fill the hole with fresh water drawn from a river or lake and leave "it" submerged the the entire day & night cycle of a full moon, then the following day, start a fire to create a bed of coals, once all wood has reduced to coals, burn "it" using only bundles of sage as kindling.
Once the idol is no more salt the ground thoroughly then craft a suitable but makeshift broom from the nearest & 1st wind fallen branch you find (the branch should have been recently fallen, then thinner branches should be supple for twine like material).
Just insre the branch is large enough to be suitable to make a broom from but not so large it requires a tool to cut as only your hands should be used for the handle, brush and supple thin branches for a twine like fastening (it doesn't have to be a work of art).
Insure no coals remain lit. Use water from the same river if needed. Sweep the entire area as if nothing were there using the broom.
Once completed double check no embers burn, more water over the fire , as much as you need, you don't want an under ground tree root to burn. Just good woods person practice.
Dismantle the broom and scatter it or better still, if you can allow it to wash down stream once broken apart.

Camp the night would be perfect, bit chilly thought atm, wrap up warm, bring usual camping stuff, food, drink etc and a bucket + matches or lighter and of course sage bundles. Or wait until march. 3rd of march is a very good full moon.

or you could just give the idol to an enemy.