I have a Whiteline rear swaybar, it didn't come with lateral locks even though I think they should. (For some period of time they did include them in the kits but for whatever reason mine didn't). On bumps whilst cornering I'd get a knock sometimes in the rear LHS.
The whiteline lateral locks kit isn't particularly good (they can move and since they are a crimp once design cannot be reset and recrimped).
Also I looked at stainless steel shaft collars (probably the best solution), but they were something like $20.00 each at the local nuts and bolt store???
After some googling many people have had good results simply using wormdrive clamps and rubber hose.
I bought a small length of heater hose (double wall with reinforcement so it's fairly thick), and cut to length. The swaybar is 20mm diameter but in actuality the diameter is more like 22mm due to thickness of the paint, so allow for this when you cut your hose. Get quality stainless steel clamps. Total cost $7.50 for hose, $3.50 for 2 x clamps.
Clean the swaybar on the inside (towards centre of car) side of the swaybar bushes then simply fit the rubber hose against it and clamp on tightly. Check after a few weeks to ensure it has not moved. Done, no more knocks.