You must be in a third world country or a very poor area for some students not to have cellphones? Well, a lightning network node does not have to run on a cellphone ..and you surely have some computers or notebooks that you can use to demo these transactions?
In a way, I think you are doing something that might deviate from your love of Bitcoin. The more Alt coins we add to the Crypto currency scene.. the less interest will be in Bitcoin and that is your passion ... right?
Couldn't be further from the truth. I live in a considerably powerful country that has one of the highest standards of living around. 10-12 year olds are at that age where some parents want them to have a phone, and others dont.
I do agree with the second part of the statement, I really want to avoid promoting alts as to not distract the students from the true store of value.