While you have good intention you need to go to a vet and forget about those specific home remedies.Honestly the only reason I decided to try it in the first place was because I found comments on several different Youtube videos, etc. of people successfully using Amoxicillin and Cefradine to treat their snakes. Not to say that Clindamycin is the same thing, because obviously it's a different antibiotic. And I would never have used it had it not been listed on the website of a serpentologist. As for dosage, that was my major concern as well. I don't want to poison my snake with antibiotics. The Clindamycin capsules are 300mg each. The recommended dosage for snakes is 5mg. That gives about 60 doses per capsule. Obviously all I could do is eyeball it, but I erred on the side of caution and used very, very little of the powder.
You do not give antibiotics without having a proper diagnoses, giving any antibiotic just because you have it on hand or giving one just in case are both as bad and should be avoided.
The first thing a vet will do (if the vet is a QUALIFIED herp vet) is a culture to know which antibiotic is best suited for your snake.
In the mean time (and I can only encourage you to make an appointment as soon as possible for proper diagnoses) you can buy F10 and and a nebulizer and use this until your snake is seen by a vet.