For ascaris, I feel eating coconuts and papaya with the raw papaya seeds worked better than the mebendazole personally.
For large parasites I always felt it would take more medicine to kill them. I had a roundworms crawl over my skull for years. It's a terrifying experience. Eventually I had enough and starting crushing them in any way that I could. I'm not saying this is the best answer but it's a desperate situation and it's what I did.
For the ones that were accessible this is what I resorted too and possible solutions.
1.) .1 to .05ml of H202 in a 1ml syringe injected into the parasite.
Went to surgeon to convince them of the large roundworm in my calf. Refused to do surgery. This parasite was extremely large (base of knee to top of ankle). I could see it,they acknowledged they could see it. Nothing happened. When injecting, I hit it probably 9 out of 10 times initially. Other areas were hit and miss. This causes tissue damage to the surrounding sites if you miss it. Again, weigh the pros and cons. I felt for large parasites that size I couldn't take enough medicine to kill them and I wanted to somehow eliminate it from laying eggs. I understand your situation of it being accessible and not being able to kill it. This is what I chose. Be wise and do not inject anything near your face, neck or other vital area of your body. I injected this in muscular tissues only, my quadraceps, pectorial muscles and calves where I knew exactly where the parasite were. I'll probably get alot of flack about suggesting this. However, it did work for me. You can atleast seriously wound it and finish it off with other means. My largest roundworm was nearly 2 feet long and I killed it this way in my calf. I felt medication simply wasn't strong enough.
2.) DMSO solutions and essential oils. I generally don't use carrier oils. Clove oil burns, peppermint burns, oregano burns for me. If it's there you can use the oils, maybe coconut oil, peppermint and your killing oil to help kill it on your skin.I'm just recently doing this and I think it helps.
3.) Crushing it between your fingers. This will cause damage to your tissues, ruptured blood vessels potentially, bruises. However, it kept them in one spot and I resorted to injecting them when they were sedatary. This is not the best approach I know, but I killed more or less 15 different worms this way over the years and I don't personally regret it. You have to weigh the pro's and con's for yourself.
The raw papaya seeds and coconut help me alot. The seeds are more effective than any of the papaya seed extracts or powders that I've tried IMO.
The Liposomal solutions work. It may not be necessary and maybe it's best to try dousing the oils over a cube of Sugar first to see if you can accomplish the same thing. Currently having CNS issues from the Liposomal solutions. Dizziness, fatigue and temp control issues. Although I'm putting too much oils in the solution.
Around the cysts there just seems to be a jelly fluid like solution there. As always my macrophages and dentritic cells apparently are content to do absolutely nothing.