Hi,
I offer lava shell treatments along with aromatherapy massage.
Be careful you don't under price yourself for this as the sachets cost quite a bit per treatment.
As a guide, charge:
normal massage price + cost of sachets + extra 20% for being a specialist treatment = price to charge
This will give you a bit of room to run promotions when needed too.
2 shells will keep hot for 45 mins of treatment
4 shells will give you 90 mins of treatment (activate your 2nd batch 30 mins into your treatment)
Construct your treatment packages around this basis so you don't waste the heat!
hope that makes sense!