All I have done is spend spend spend on my car recently, I am up to about

 

From what you are proposing, it sounds like you are just going to clean up the lamp. There must be a reason the lamp is taking in water that needs rectifying. Surely by just cleaning and putting in a gel sachet is only a temporary fix.
I would say that there must be a seal somewhere that is causing the leak. Maybe the glass needs removing and resealing to the headlamp body. What is the condition of the reflector like. If it has sat in water, is this not corroded?

 

it's a very common issue. the seals are prone to failing. what people do is

1. Remove Bumper
2. Remove lamp (do both?)
3. strip down all the bits, clean it as you say and put somewhere warm to dry
4. redo the seal - many ways of doing this, adhesive, sealant
5. refit

mine occassionaly steam up but then it goes away.

 

Cheers thanks for that, will give it a go!!!!!

 

plenty of posts here too - do not heat them up to 200C in the oven (if you search you will laugh your head off)