Good old fashioned heat. Most seeds won’t tolerate temperatures above 60oC for more than about 12 hours. That’s still plenty cool enough not to damage the bristles.
In warm weather, you can easily achieve these temperatures by placing the seed in a black garbage bag an leaving it in the sun. You might need to leave it out there for a week or so to get enough time at the high temperatures.
For most seeds, the process works better a high humidities. So wet a couple of paper towels and stick them in the bag with you seed…