So I did some research on these products and here is what I found out.
Not sure about preventing slime and for hydro, but for soil, products like this have to make contact with the roots when transplanting.
Spray the soil where the root ball will be transplanted to in the larger container.
"there are only two known endomycorrhizal fungi species which colonize the roots of cannabis/hemp.
They are Glomus Intraradices and Glomus Mosseae."
Here are some other helpful facts. Did a comparison of the available products on the market including great white, subculture m and B, ZHO and many others. Here is what one person who knows his stuff responded.
"BioAG Vam is the only product I'd recommend. VAM includes seven species of endo-mycorrhizae with a heavy dose of the aggressive Glomus intraradices, It should also be noted that VAM contains only endo-mycorrhizae so growers aren’t wasting money on ectos that only associate with trees.
The MOST IMPORTANT aspect is that VAM does not contain any Trichoderma which is cheap, the spore count for it in these mixes usually eclipses all the other organisms put together. Unlike endomycorrhizal fungi, Trichoderma requires no root contact to sprout and grow. In addition to this, its favorite food is other fungi...... guess what happens if your chosen product contains 10,000 spores per gram of Trichoderma and 100 spores per gram total of other fungal species.... think highlander"
Don't waste your money if your not going to do it correctly.
Hope that helps.