John,
We use both Cobalt and combination dryers in the printing industry for much the same reasons. You are probably going to discover that you get a crusty film on the top of your finish of choice with cobalt drier, since it works with contact with atmosphere, and humidity level changes the reaction. So does exposure to UV light, if I'm not mistaken.
If Japan is working, stick with it, and try to perfect your technique.
Best,
Ted