My cat's tail problem

Dear Cat lovers

My cat seems to have a small problem with his tail. He has been in our home for 5 days now and while playing with him I noticed that he has a kind of blackheads on a part of his tail. He has been neutered about 3 months ago. I mention this fact because I've heard that not being neutered can cause problems like this to cats. 
Is there any special shampoo that I could use? How else can I eliminate this problem? I will meet the vet next week, but maybe I could do sth until then on my own  

Greetings!
Magda

I would leave them alone until you see the vet.  Where are they on his tail?

It's about 3 cm from where the tail begins  

On the top side of the tail or the underneath side?

On the top

Hmmm...it could be just about anything from flea bites to something else.  Get him to the vet for a check of that.