I have never seen that being taught and quite honestly if you want to make money in your time - ie speedwaxing you simply cannot have the time to drizzle wax from one spatula to the other.
Time is money and i would rather waste a disposable spatula than waste the time "playing" with wax.
My daughter was taught drizzling also (same college i would think as same area)
I would say it is fine to do for using strip wax on small areas but it probably wouldn't work well at all for the hot waxes and as you say its not very speedy for full leg work.Im not sure whether they did drizzle for large areas or only the intimate underarm and face my daughters not here at mo so can't ask her.