"........ Have decided to attempt to grow sweet peas from seed........."

"....... I always soak mine overnight in cold water ...."

I find that hard coated seeds be they Sweet peas or Banana or what ever do
well if you put them to soak in quite hot water(Not hot enough to cook them)
and leave them for 12 hours.
The heat drives out some of the air within the seed coat and then as the
water cools you get water drawn back in, a lot easier than trying to file
the seed coat.

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk