I can only tell you what experience has taught us. Breeding Sizzle back to Silkie only strengthens the silkie feather gene, producing more silkie feathered birds. Since Sizzles don't have Silkie feathers, that seems counter productive. If you are taking that generation and breeding back to Sizzles (frizzled) then you may improve your type & get proper feathering but, your still looking at only 20 - 25% success rate. Which isn't any better then your frizzled cochin/silkie cross. Plus you have to find a Sizzle Roo that is producing type & the breed is just starting to get to that point.
SarahsSizzles
SarahsSizzles