Instead of casting a spell on a person normally, the spell is suspended at the point of casting within the binding, until it is released by either the trigger decided by the person that made the binding or by the binding decaying - which you're not sure whether it would happen, perhaps the Ulgu would fade with time or perhaps it would continue on based on ambient magic. You'll be keeping an eye on your chicken, but it's already outlasting the Dhar bindings.
The nature of the binding means it must be suspended within a living creature, and that the spell will be released 'within' said creature - which means that it works entirely as expected with spells like Sleep and such, but it's incompatible with spells that would normally target you and would probably end messily if you tried it with Shadowsteed. It might be possible to do it differently, but it would be a lot harder to redesign the bindings from the ground up than adapting the bindings you studied previously for use with Ulgu.