Germinating Eggplant Seeds
Your question is really several questions, but I think I can answer all of them well. I've grown many varieties of eggplant from seed.
Can I grow Eggplants from freshly harvested seeds?
Yes. You can grow eggplant from fresh seeds. In fact, you don't even need to remove them as you have done. In an overripe eggplant the seeds will sometimes germinate before you cut it open. It's a nightshade, (Solanaceae family) and similar to tomatoes, you can plant very thin slices in shallow soil that will often do better than seeds that have been removed. The remnants of fruit flesh in decomposition contribute compounds that naturally aid in germination. A very light spray of hydrogen peroxide at this time will contribute oxygen and reduce pathogens.
There's a very interesting study about it here (by the NIH) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6930571/
If not, I assume I need to dry them out - Can I just dry them out for
a few days and then try and get them to germinate or do I need to wait
a while? Do I need to put them in the fridge/otherwise stratify them?
No,no,no
Don't dry them out. Don't put them in the fridge. Don't scarify them (what I assume you meant when you said "stratify" them). Stratification can involve prepping them with heat or cold. So, yes to heat and no to cold. Eggplant need to be kept warm before, during, and after germination. For germination, 27–30 °C is best, but definitely not below 20°C
Am I better off direct sowing the seeds or putting them in a damp
towel in a bag on a heated bed to encourage the seeds to germinate?
(Daytime temperatures are 14-20, nighttime temperatures 8 - 17
depending on cloud cover)
No, and Yes.
It's too early for direct sowing outdoors. Start them indoors and only put them outside when the weather gets warmer than it is indoors. Put some of them between two layers of moist paper towel, and put some others near the surface of a thin layer of clean moist soil. Keep them warm, keep them moist, and keep them covered. You can rinse the ones on the paper towel every few days.
They don't need light at first, but they will after the first set of leaves have sprouted. That's when you should put them near a window. When a root begins to develop (about 1 cm) then I transfer them into those little yogurt cups individually with my best soil (with holes in the bottom of course). If the root has embedded itself into the paper towel, then separate them by cutting that portion of paper towel while leaving it attached to the root.
If you want to avoid all the fuss, there is a similar method explained in this YouTube video https://www.youtube.com/watch?v=2RX5CANe5KE&t=24s Personally, I like playing with them and watching the germination, and my method takes up a lot less indoor space, but I especially like how the gardener in the video uses worm castings. I'm a big fan of that.
The only other important tip I should mention is to make sure they don't get too soggy. They have to be kept moist, but don't let them soak. Good luck!
