jullieh you can get tricide neo from the USA, even if you live in the UK. I live in France and it's not available here either, but I ordered online from the very helpful owner of Pondrx.com. He took my order over the phone, and I received the pack within about 10 days or so.
I don't remember the exact details, but I know that I divided the pack into 4 doses, making one batch of liquid at a time. I filtered and re-used each batch of liquid for at least a week (washing the bird's feet in plain water first before you dip them in the medicated liquid helps to keep the tricide neo clean) and I placed the bottle containing the liquid in a bath of hot water to warm it up before each use.
I have no scientific evidence, but I can assure you that I had tried everything beforehand to no avail, and within 3 weeks of using the tricide neo (every evening, for at least 5 minutes at a time per bird) the bumble on my girl's foot had dried up and fallen out. It left a hole through the foot (like an earring piercing) but it soon healed
It takes a bit of time each day if you have more than one bird to treat, but for me it was well worth the effort.
I haven't read all the thread, so I don't know how many affected birds you have, but if it is a recurring problem then maybe you should look at your perches. I have wide rough boards as perches, but since I placed pieces of old towelling over each perch I haven't had a single case of bumblefoot. The rough, square edges of the boards were no doubt contributing to the problem with my girls.
I remove the towels from the perches each week, soak them in a bowl of hot water and washing up liquid (to kill any red mites that might be nesting in them), then I put them through the washing machine (to clean all the poop and stuff), but that is a small price to pay - I haven't had any bumblefoot in my flock for the last two years, whereas I had it regularly up until then!
Hope this information helps.