Hey apalnt21...it might never happen, but knowing how to make charas might come in handy one day.
for example if you are walking along a trail in a place like Nepal and come across a stand of wild ganja in late flowering...you could cut branches down, take them back to where you are staying, dry it for a few weeks at least, then sift it if you have screens, you could do the same without drying and ice hash it fresh if you have access to ice and Bubblebags, you could also dry the buds and extract the THC with chemicals if you have that and the equipment needed with you ....or you could rub the resin off the live plants and after five minutes work you would have enough for a few pipes of charas.
You might be in a country with lots of poor to ok quality pressed brick weed and after a few days you aren't getting high anymore and your throat hurts then hand rubbing the dry buds will get you a less harsher smoke and harder hitting high. ..this is something you can do in your hotel room without any special equipment..and the added bonus is that the hash you make will not stink as much as burning bud and it's easy to conceal a marble of hash compared to an ounce or two of weed.
and those who are paranoid about skin, wash your hands with soap and sand, this will remove any old skin on your palms.
Hand rubbing is a skill all ganja travelers all should know