How big is your opening into your fermentation keg? A small opening (like a carboy) limits your options to those that can fit through the hole. The SS pickup tube screen (or cheap panty hose) really won't work well for a substantial load of hops (be it pellets, leaf, or whole) or spices/fruit additions because there's too little surface area and too much suction force at the opening of the dip tube or pickup tube.
The ideal solution involves 1) increasing your screen's surface area, and 2) distancing the screen/separator away from the opening of the pickup tube, thereby decreasing the chances of clogging the screen due to too much suction force. The latter is somewhat analagous to controlling your runoff speed in order to avoid a stuck lauter.
I remember a holiday ale where I had problems with the orange peels in the secondary clogging my racking cane--I used a sanitized nylon mesh bag over my racking cane to complete the transfer. I still noticed significant tendencies to clog due to the suction force at the tip. However, since the bag was long enough, I could simply tug on the side of the bag and move the tip to another location within the bag and thereby relieve the obstruction (the water column within the tube maintained the suction and allowed me to restart the siphon).
Theoretically, if your opening is large, one could make a cheap and more effective solution using one clean and sanitized plastic whiffle soft-ball (pre- drill extra holes if you wish), a clean and sanitized nylon stocking (full length), and one clean and sanitized racking cane. Put the ball inside the stocking (all the way down to the foot), insert racking cane (with or without the protective end cap) and get the end within the ball, and advance the stocking all the way up to the bend in the racking tube and secure. Sanitize in StarSan and drip dry for two minutes before use. Now you have 1.) massive surface area for screening and 2.) significant distance between the screen and the pick up tube entrance. You should not have a clog. If your opening is narrow, you'll have to use a CPVC tube with multiple perforations and employ a tube within a tube approach along with the mesh bag or nylon stocking.