I've never had much luck pouring a lot of hot wax through a filter because it has to be kept warm enough to stay liquid, but if you pour it through with hot water it will usually work - but it has to be poured into a big container, otherwise it overflows and you end up with a mess
Wax in a bain marie jug will stay warm enough to be poured, I've found the best way to do that is to stretch a pair of tights across the top of the jug - but the wax can't be too dirty otherwise the filter gets clogged up with gunk.
One way is to put the wax in a
very low oven, at the bottom of the oven to be sure it doesn't overheat. Let the wax drip downwards through a filter and into a container - JBM's method of using a tin and an old pair of tights works very well, but it's a bit hit and miss if you cook with gas.
Another way is to use a pan of water (in hard water areas it's best to use rainwater, especially if you want the wax for show) and encase the wax in a filter (lint, muslin, J-cloth, old tights, bits of net curtain or similar) and weight it down. Heat the water until it simmers, then turn off the heat. Keep heating until all the wax has melted through the filters and is floating on the top of the water. Leave it to cool. There will be a layer of gunk under the wax which can be scraped off. If you want it really clean (for show) you'll need to do this two or three times.
You could use steam or a solar extractor and filter the wax at the same time. I know some people who use an old Burco-type boiler with the thermostat set very low, they put a brick on top of the wax.