Hi,Dear,Thanks for your query to HCM.
Studied your query in full depth of its details.Reviewed it in context of your health concerns.
Based On the facts,You seem to suffer from-severe form of 
Onychomycosis,which would need Oral Tab-Lamisil(Terfenadine) 250 mg once a day x for 3 mths.which is a proven treatment in Onychomycosis.
If need be Debridement of the Nail and nail bed may be needed in your case if the 
oral therapy needs the support of Surgical or 
Laser Debridement.
Hence Local sprays would not be helpful in your case,as experienced by you.
Keep the part dry and clean with 
dettol sponging locally.
Take your treatment  under expert doctor's cover.
Hope this reply would satisfy you and would help you to plan further treatment
with your doctor there.
Welcome any further query in this regard,which would be replied in next session.
Will appreciate YOU,to write your excellent review feedback comments of this service experience, to help the needy patient visitors like YOU, at HCM services.
Good Day!!
Dr.Savaskar M.N.
Senior Surgical Specialist
M.S.Genl-CVTS