If a boot was not designed to be waterproof it will never be.All the stitching holes are perfect capillaries to conduct water droplets inside the footwear.It appears the Courtney is a stitchdown type construction which is made without a welt,the upper leather is simply sewn through to the midsole.Stitchdown construction will never be waterproof without a waterproof membrane such as Gore-Tex.
Wax is generally not the best method of waterproofing leather because it does not absorb into the leather.It stays on the surface and is easily removed.Walking through snow for example will do an excellent from removing it.It also attracts grit which can grind itself into the pores of the leather.
Sno Seal is primarily beeswax and was developed for ski boots.It contains no oils or silicone which enter the pores of the leather and are effective waterproofers but also soften the leather which would be undesirable on a leather ski boot,you want it as stiff as possible that's why they are made out of plastic today.Sno Seal was also used for skates for the same reason.
Thompsons water seal is actually a good waterproofing for leather they actually say so on the can.It fill the pores of the leather and has good staying power.
Aqua Seal is the best I have found.It has silicone and a diluted wax.You apply it and the next day there will be a slight wax haze which easily buffs off.You can actually feel how it 'fattens" the leather with silicone and the diluted wax protects like a coat of wax on your car.Beeswax is too soft and gooey to do that.
In the end Pheroze your Courtney Boots are beautifully crafted but meant to be enjoyed in the dry conditions of Africa and I hope you get to wear them out to tatters there.
Best Regards,
Shoedog