I've done the drip-acclimation several times and never had any bad effects from doing so. I don't usually leave them in the bucket for more than an hour. Puffers, especially brackish ones, can adapt very easily because in their natural environment, they would get variations between fresh and salt anyway with the tides, etc. So I would not worry about acclimating the little puffer.
As to the issue with ich (whitespot) .... first thing I would do is start raising the temperature, 1 degree F per hour. Actually, you can kill off the parasite just by raising the temperature, but of course, you can add the salt too, if you want as that will also help. But if you didn't have any, you could just as easily get rid of the ich by temperature control too. If my memory serves me right, I believe the parasite is killed at 89.5F. I f your fish can handle that temperature, if you keep your tank at that temp for 6-7 days, it will effectively kill off the ich parasite. After the 6-7 days are over, reduce the temp to 86F and hold it there for the remaining days until you've had the heat up for a combination of 10 days. Make sure to have an air stone to give more oxygen whilst you have the heat up, and do daily water changes of at least 25% while you are going through this treatment. This WILL kill off the ich, whether you use salt along with it or not.
I hope your little puffer doesn't have ich, but if he does, just follow those directions and you should be okay. I don't bother with medications any more, I just turn up the heat, and I've never lost a puffer yet since doing it this way.
Good luck!
I have had a tank up and cycling for 10 days and I have it brackish (low end 1.004) I have the temp at 80F. It is a 46 gallon tank and I am running a 110 aquaclear and an already established (good bacteria) 50 aquaclear, which I will remove once things are cycled fully in the tank. Do you think that is too much filtration? I also have an aerator running. I am picking him up in 3 hours and I need to know what else I need to do? I know all about adjusting him slowly to the new water and temp etc. My question is then what do I do about his ich since he is sure to have it they tell me? Is the brackish salt (I used instant ocean) going to help him or do I add normal aquarium salt? I have spent $1000 in the last 2 weeks on a new aqurium and filters and good decorations and I want this to work out sooooo badly this time. I have read everything I can and I want to be the best Puffy Mommy ever, lol. Any advise you can throw at me in the next bit would be very much appreciated, Iknow these little guys are tricky and I fell so hard in love with the last little guy that I just don't think I can handle losing another one 
already so I will have nice yummy baby snails soon.
