Is it true that a lot of stff get cleaned away by the acid in lemon and vinegar
i mean its like the nature of the show!

Quite true, but you need to always follow their tips with care.

There is some bits and pieces of discussion on here which refers to what uses they have as well as using search engines for uses also.

Lemon, vinegar, bicarb of soda & soda crystals are all great for cleaning, but as QL says, be careful when using them

i find a mixture of lemon & vinegar good for cleaning my mirrors in bathroom - stops them 'steaming up' for a while

A paste of salt and lemon juice is excellent for cleaning copper objects. Apply, rinse off then buff to a lovely shine. Do wear gloves though as this dries your skin something awful.