Are you planning on sowing the soaked seeds in soil?

If you do, you should also consider the possibility that the mutagenic molecules might be degraded, diluted below the effective threshold or percolated by watering. Degradation is a problem also on plate.

There are several antimutagenic agents present in plants to inhibit pathogenic processes resulting from infections and/or exposure to mutagenics and/or carcinogenics.

Mutagenics are not an efficient way to repel herbivores due to the long time and the required management, because they would likely be dangerous for the plant itself, therefore neither common nor powerful.

Colchicine and katanin are already widely studied due to their use in molecular biology, but some flavonoids, in particular flavonol aglycones, have been shown to have such effect (i.e. quercetin, kaempferol, galangin and myricetin.

You could extract them all as an acid hydrolysate of green tea.

You can use the seed or fruit extract of Datura metallica. It works very effectively as mutagen. We have released one lentil cultivar develop by using the Dautura metallica seed extract mutagen. Alternatively, you could try also the chilli extract.