I use the jone's spikes and they work fine. NO need to spend the extra for the water plant spikes.

I also like to use osmocote in my lilies when I repot them.

I use Jobes tomatoe sticks or tree spikes broken up into small pieces about 3/4" inch in size and they work fine.
My lilies get two/three chunks per month and potted maginals get one chunk at the begining of the season.
The fertiliser sticks for tomatoes or fertiliser spikes for fruit trees, seem to be the nearest to the actual N. P. P. of the aquatic fertiliser tabs. The fruit tree spikes are a bit higher in the phosphate and potassium content, but not by much, than the aquatic tabs.
I have used them for years without causing any problems.
Just go easy and don't overfeed, as with any type of fertilising.
"Horton"