The roots do get to the bottom of the bucket, in the usual root growth time, the water does 'wick' up as well
I think Osmocote is a volcanic rock with similar properties to hydroton clay pebbles. If you have enough water retention young seedlings and clones work amazingly!
I've done 100% Perlite hempy's, these aren't great as you need more water retention in the medium for early stage growth, and you need to water pretty much daily :/
Also done 50/50 Perlite/Vermiculite which works the absolute best out of what I've done as the vermiculite gives great water retention and the perlite gives drainage.
Finally done 60/40 Soil/Perlite this is the second best but you can use organics with the benefits of a reservoir.
You can also do 100% Coco Hempy's as it has good water retention and drainage properties, I reckon though, you'll have to water 2-3 times a week. Just an educated guess
Definitely try hempy it is so damn easy, it's actually impossible to over-water
I use 10 litre and 2 litre hempy's, the 10 litres I can thoroughly water once or twice a week and not have to worry and the 2 litres I water about 3 times a week.
At the moment I am experimenting with yield in the 10l vs 2l pots, so far the plants in the 2l pots are bigger than the 10l ones and have stronger colas at the moment
we'll see about the final yield. (maybe it's because the smaller pots get flushed out more so the reservoir isn't stagnating or fluctuating PH too much) But it's an experiment and we'll see XD
Stay Frosty!