Casting a slinkie on a fly rod is an abuse of the rod!! as is excessive splitshot or even too heavy of a fly. Don't complain to the manufacturer when it breaks.

if you wanna use slinkies to drift fish a fly do it with the appropriate rod not a fly rod...

First of all if you need a slinkie you are fishing water that's not fly water..

Second of all if you want to get deep on a dead drift try a sparce pattern on a mustad 7970.. This will get a fly plenty deep, then if you still aren't getting fish it's not because oh how you are fishing!!!

There is a great misunderstanding about winter steelheading, people coming from the trout of even summer steelhead backgrounds seem to think that if they don't have immediate of consistent success that they are doing something wrong.. Fact of the matter is fly fishing for winter steelhead is TOUGH!!! You're not going to get bit very often.. If the frequency of your hookup's is not up to your standards then maybe winter steelhead fly fishing isn't your thing...
Winter steelheading is ALL about perserverence, discipline and even an enthusiasm for an unproductive day. Now i am not saying this to be mean or elietist but if what matters to you is putting fish on the bank then by all means put the fly rod down!!!

no one else will say it so I will.. using a slinkie on a fly rod is not and cannot be considered fly fishing. It's drift fishing end of story, all that said I love drift fishing when done with the appropriate gear...