Patience is really the answer. I paint figures with oils and just normally place my figures in a plastic, dust free stowage box and allow them to dry. It often takes a week or so, especially for white colors and light gray shades.
However, you can build a small drying box with an incandescent light bulb as a heat source. A dust-free box, like a plastic storage bin with a close fitting lid is better than a cardboard box, but a cardboard box would work. You could use a shop light on an extension cord or buy an inexpensive ceramic light fixture and attach a cord to that.
Some figure painters build a design purpose drying box out of wood and mount a light fixture in it with pieces of filter material over the venting holes to mitigate dust. However, I've just learned to be patient and allow my figures to dry naturally.
Use a low-wattage bulb - ~40w or lower maybe. Allow some air circulation by making holes in the bottom and top of the sides. Keep the bulb away from the sides and top of the box and not too close to the model (depending on its base material - white metal, resin, or plastic - each tolerates the heat differently). You don't really want too much heat, just enough to get the inside warm and to cause convection circulation of the air.
Monitor your set-up to be sure it's not a fire hazard or is not getting the box or figure too warm. If you're not sure, turn the light off when you're not present until you are sure your design is good.
You can do an internet search for paint drying boxes to see various designs. A commercial source for a drying box would be the boxes made for drying fruit or meat jerky. Those often have temperature and time settings.
Slow drying time is probably the major drawback for using oils, but that's also why they're so easy to blend. I'll live with the drying time for that advantage.
HTH,
. Has anybody any ideas 
how to dry the paint quicker.
