My blocked ear was driving me mad. In the past, my surgery would have syringed it for me but the NHS apparently no longer do that. Rather than visit Specsavers or Boots, which looked like it was more focused on hearing tests and selling hearing aids, I thought this was worth a try.
I had been using olive oil (and Otex) for a while up to this point so the wax was softened. My advice is to use warm water (body temperature), don't insert too far into the ear canal (leave a slight air gap to avoid pressurizing), and don't rush. It took 3 or 4 syringes full for me but relief came within a few minutes.
Best of luck!