Question about cleaning

[mosquito]

Hello!

Came to me with oil painting on canvas . But was seen in severe conditions , as very dirty, sooty can say something. What simple means can clean it and to do no harm ? Read that you can and foam swabs from children's soap . Is this true? What else is possible?

thank you

[Toinen]

Сообщение от mosquito

I read that you can and foam swabs from children's soap

Strong soap and dirt off.
A coagulated and yellowed varnish - even more so.
I advise you to consult a professional restorer, you can not handle yourself.