I have also been experimenting with different mediums and have found one that is wonderful to paint with. I am loving it at the moment and will keep you posted in case it goes disastrously wrong somehow ;-)
Here is the recipe if you are interested:
1 part stand oil (W&N)
2 parts purified linseed (Holbein)
2 parts Venetian turpentine (Talens) - this is a balsam and looks like stand oil
2 parts pure gum turpentine and 5% cobalt siccative (Roberson).
I had been trying a Dammar varnish mix but didn't like it as it was too tacky for me.
The cobalt dryer is poisonous so please take extra care if you decide to try this mix (I needed it so I could get back to work on the paintings the next day - only the W&N ivory black and cadmiums took more than 24 hours to dry but you will have to experiment).
I have always used Liquin Original up to now, but I am just experimenting for that 'perfect' medium.