I don't bother diluting meths anymore. Some meths is already diluted when you buy it.
It reduces the boil time and when undiluted the meths hardly creates loads of soot. Just wipe the pans on the grass or with a small cloth. You don't get any extra meths by diluting because it takes longer to boil so you use the same in the long term.
Don't put it in a bottle that can be burst or may leak, the meths smell on your kit will never go away
A Sigg bottle would be perfect. I use a Trangia bottle which is also very good.
I've just done 3 days away and used about a quarter of a litre, but that was leaving it burning to warm my hands up as it was failry cold at night.
As said above, i don't bother diluting, can't see the point really.
About 10% water in UK menths, and a bit more in French meths
How to measure.
Fill up the Trangia burner with meths to the top
Wait a few seconds and the level will fall as the outer chamber fills
Top off with water
If cold, then top off again with a small amout of meths and light immediatly (Meths is slightly lighter than water, so pure meths lights faster, whereas meths/water mix can be difficult to light when cold)
To boil a full kettle I should say about 12mm in the bottom. Just pop the cap on to the burner ( not the screw top ) and it'll extinguish, you can then let it cool down and put the screw cap back on or pour the meths back into the bottle.
I usually fill the burner and that gives me enough to boil a full kettle and do a bit of cooking/warming through . DON'T fill the burner if you run out of meths when it's still hot.
The sigg bottle will be fine because that has a rubber seal on the top. The small Trangia is just a mini stand/sheild burner pan & teflon frying pan. It hasn't got a kettle but the the frying pan fits onto the pan to help it boil quickly.