Although cutting off funding is highly effective for some of these more organized groups, unfortunately the groups that I followed are often individually backed by ardent supporters and ideologues. Cutting off the funding will stop some of the problems that stem from being able to financially bolster a movement. We can't overlook the fact that these are, often, ideologically motivated people who will do it free of cost. Some of the most vociferous posters have no funding, other than their own BitChute channels.
As far as other alternatives are concerned, I would be very tuned into how VPNs are utilized. We can crack down on what people are accessing here in Canada, but anyone with a Netflix account knows that you can jump onto an American account and then you get better films. It's the same thing with extremism, unfortunately. You can dodge these government checks and balances quite easily.
It doesn't answer your question or provide any useful help, unfortunately. It just raises more concerns for IT people.