cliveh, your post "I would never use a squeegee and can't understand why they were ever suggested for photography."
I use a very soft squeegee with a very light touch on film to remove and clumps of grain that can cause an imperfection on the print similar to a dust spot, learned this in an advanced printing workshop years ago.
Perhaps I am not up to speed here, but isn't the grain within the suspension of the emulsion?
Seems to be a bit of variation in process in the responses. My second suggestion would be to try the suggestions one at a time until you find a procedure that works. Then, if it ain't broke, don't fix it.
FWIW, I've heard WWII reconnaissance aero photographers used to give their films a final soak in alcohol and then light it to dry the film quickly. But, I wouldn't try that at home.
I love these threads about drying marks. Fifty different people will give you fifty different solutions to the problem. And another fifty will tell you they have never had anything but perfect negs all their lives, despite rinsing their films in the old dishwater and wiping dry on the end of their sleeve! (I have since discovered that some of those with perfect negs have just got low standards and/or poor eyesight!)
Anyway, here's my two cents worth...
In my experience, the marks appearing on your shots do look like they are caused by the wetting agent (PhotoFlo or Ilfotol). The sort of marks I used to get which looked like this were effectively in the emulsion, and once dry they were permanent. So cleaning the shiny side of the film does not help. For me, the solution involved mixing minimal wetting agent (much less than 1:200) with distilled water together with a dash of isopropyl alcohol in an open dish (as suggested by Les McLean). It is essential that the wetting agent is very thoroughly mixed in the water. My film is then see-sawed through the mixture a few times and hung to dry in the normal vertical fashion.
Assuming your problem is the same, I think what works for you is likely to depend to some extent also on your local water supply and climate. I suggest experimenting with different amounts of wetting agent, and then watching very closely how well the water runs off the emulsion side of your films when you hang them up. If you can see any rivulets or evidence of viscosity, you may need to make some adjustments.
I hang film and spray both sides with distilled water using a squeeze bottle and a tray underneath to catch the runoff. Never have water marks or dust problems since i started. Also got off the photoflo habit, not enough dilution caused similar looking problems IMO.