People have been using Mr.T's "super solvent" in hard to create concentrations for some time now. The main chemical is a very potent solvent, but not a bacteriostatic or bacteriocidal agent like the other potent solvent benzyl alcohol. therefore it is require that you add such an agent as Mr.T has done with his kits.

Here is the chemical that is used in those kits; Guaiacol AKA, alpha-Methoxyphenol , or Pyrocatechol Monomethyl Ether.

Molecular properties can be found here: ortho-guaiacol 90-05-1

Guaiacol has been shown to have anesthesic properties, though to what extent I can't comment personally on. This fact is probably why solutions in high concentrations using the super solvent are reported to be painless or nearly painless by users.

Guaiacol is a creosote derivative and is commonly used in cough and cold medications in the US.
It has been shown to have irritating properties on inhalation, injestion, or skin contact in high quantities. It permeates the skin barrier very readily and will be distributed systemically as well.
Guaiacol is a combustable compound, so be very careful when brewing this if you use an open flame as your heat source. i would suggest everyone have a good hotplate with automatic, magnetic stirring if you regularly homebrew though.

Suggested use.
Most recommend 2ml guaiacol/1g of hormone you wish to suspend. You will want to use 1-2% benzyl alcohol as a preservative along with the guaiacol if you are not using Mr.T's premade solution. If you are using the premade super solvent there is already an antiseptic compund added, common use is 2.5ml/g of hormone in that case.