How to clean the grass pad? And how frequent it should be cleaned?

You can use hoses and soapy water to clean the grass pad, and allow to dry completely. It is better to hose it every other day. The product comes with 2 pieces of dog grass pads, you can switch and use them.

How can I attract my dogs to it?

If they currently use wee pads you could try placing one on top of the grass, preferably one that is already soiled slightly so it has the scent. As they start to understand, remove the pad. Or, you may try the attractant sprays.

Can I use this inside my apartment as a dog potty grass pad?

Yes, you can, dog potty grass is one of the most popular uses of TiiDOW grass pad, there are perforated holes in the bottom so water and pee can drain through, we suggest you buy a tray(suggested size is 35inch X 23inch) under it to collect fluid.

Does this grass pad shed grass fibers?

When unroll the grass, slowly tear off the tape that connecting the tube and grass, gently cut the black strings on the edge if any and blow off "loosing stuffs" after cutting. According to above steps, the grass fibers holds together pretty well.

Is the grass mat thick or flat?

The grass mat is thick and packed in roll. Its blades will be fluffed up after you unroll the packing and put the grass mat in the sun for few hours.