I've never used a compressor and never had any problems.
the way i do it is to attach track pump, lay wheel horizontal on a bucket, wipe very thick soapy water around the rim/tyre gap (both sides) with a brush, i use a dustpan brush, then pump.
if it goes up, then all good. pump up to pressure, and you'll hear the beads seat properly, they will 'pop' into place and leave 1/2 hour. then deflate tyre, carefully nudge the tyre off the bead on one side, put in the sealant, and then re-inflate with some more soapy water.
You don't need a compressor, but some find it hard to get any pressure without one. Some use co2 gas