I don't know if it is any use to your boy but I am using Myristica Sebafera (30c) on my old boy's abscesses.
I am a disciple of science based medicine but a little part of me has seen great results with homeopathy (which is now considered a dirty word in some circles).
Myristica Sebafera is known as The Sword - ie it brings boils and abscesses to a head, gets them drained out and the wound mending.
At my wits' end with my old Icelandics hooves, I tried it and a day later an abscess burst and then a few more days later, totally unexpected another on the other hoof.
If you are interested in some, let me know and I will tell you where to buy it (in UK) and dosage.
I did admit to the vet that I was giving Myrstica and he, like me, said he liked science better and then admitted he used homeopathy with great results for a broken ankle!
Anyway, back with the soaking. Luckily we don't have to poultice as in coronary band. Good luck !