Rye malt and flacked rye both need to be mashed, not steeped. Rye malt, which can be hard to find, will actually convert itself, but flacked rye has to be mashed with base malts. 5-10% is about the limit for a mini-mash. Bit the bullet and get a really big grain bag. The main difference between steeping and mini-mash is the temperature.
Golly, BP, I haven't seen the Captain since I was a kid back in Illinois!