Mr.PS

I had some Engine Kote for a while I havnet really had a chance to try it out yet. I noticed though that the bottle I have it in is starting to get all out of shape as if the air was being sucked out also the sprayer feels gummed up and doenst give a mist anymore Its in a Zep Pro Chemical Resistant sprayer and bottle. I took the sprayer out and cleaned it and with water it misted perfect the spray bottle also went back to shape. What is the deal with Engine Kote does it need a special sprayer or bottle ? Does It need to be shaken once in a while for it not to settle. ?

Thanks