Can you please tell how and what better to wash oil, and how to reinforce the bed

[Тамара]

Hello, Dear!
I ask for advice. Please do not be lazy, show you how:
1) clean stains (a version that cats have written, but may simply something sprinkled) with the works of canvas /oil. Water is erased, but very, very badly, badly need to scrub. What can wash these works (soap?, Something special?) That in the future is not what led to some more trouble with an oil painting?? The very picturesque layer slavabogu almost smooth - ie Painting is not Thickly pained not invoice, slightly easier task ...
2) How to fix pastel on corrugated board - if the work is a thin layer of dust. it did not sotresh not sduesh? Just sprinkle on top of paint, if visible dust is not the way? Or try to blow a hair dryer?
 A lacquer which is better?
 And from what distance spraying, so as not to harm?
 A dry vertically or horizontally?
And then rubber stamp to cover, or no longer want? How вобще pastels store?
Phew. So many questions.
Sorry.
It is waiting for expert advice in order to proceed to the "restoration"
THANK YOU! (previously: shy