I am happy some of you tryed this technique with a succes. Lately  I have found another very promising material that can be used (beside mosaic and coarse perlite). It is called  Zeolite 
 
Wikipedia: It provides a source of slowly released potassium. If previously loaded with ammonium, the zeolite can serve a similar function in the slow release of nitrogen. Zeolites can also act as water moderators, in which they will absorb up to 55% of their weight in water and slowly release it under the plant's demand. This property can prevent root rot and moderate drought cycles.
We should all add some of it in the soilmix as well. You can also use Zeolite in your bottles of drinking water with great health benefits as it absorbs toxins ext.
Ivasilr,I don't see any problems for repoting, and actualy you can start your cutting strait into a big pot.with this technique.
JR, It is the Black Walnut that is most toxic. And since it has the best rootstock, most trees have Black walnut roots. It is the roots of the walnut that make the real toxins. Unless you are sure your neighbor's walnut tree is not the Black one I don't think it is a good idea to plant your figs near it.

Thanks, Pen.  I'm 99% sure the neighbor's tree does not have the black walnut root stock, but is just a rogue English walnut volunteer (no graft union, etc.).  This fig thing is new to me so any bit of info helps!  What started out 3 weeks ago as a passing fancy with figs has grown into a full-blown overprotective commitment :)

Thanks again to the Forum-

I tried this method using aquarium rock recently since I am unable to find mosaic in my area.  I was a bit concerned that I was damaging the roots as I (gently as possible) sprinkled the small rocks over the roots inside the tube.  I was also wondering about shocking the roots since it seems like the environment that the roots formed in (moss or promix) is so different from the aquarium rock and then there's the question of roots penetrating the aquarium rock stratum.  It's been about a week and I haven't seen any roots reach the walls of the cup where they can be seen.   Of course, they may just be slow in appearing because the temperature is a bit lower than optimal (high 60's) but I was wondering what Danny's or anyone else's experience has been using aquarium rock.  Thanks.

UPDATE
The aquarium gravel continues to be fine, cutting is flourishing with two leaves.  So far it appears to be a viable filler to ensure drainage.  I am going to use a small construction gravel next, lots cheaper.

any new updates? i plan to either use (aquarium) gravel too but i want to know which one is the best?

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