I had this same problem just these past 2 weeks. Recently bought a BM from a local store (no not used you slimeballs :twisted: ) and had a lot of hair downstairs. I was typing this problem and found a lot of sources from GLL, especially Phil and MPMD. They both said to shave the pubic hair. I tried using my shaver but then said the best words a man can say when he's faced an obstacle, "fuck it", and shaved it all off with those small disposable razors.
The two best pieces of advice for using the BM as a newbie, saying this as a newbie are
1. Shave them off, the suction is phenomenally better.
2. Use the hottest water than you can use. People have different thresholds, but use the hottest that you can use. It should feel hot but not too much to the point that it's scorching on your dick. As you become more accustomed (using it 3-4x a week) increase the temperature just like how'd you increase the weight in the weightroom and you'll have better pumps (no pun intended).