Hello and thank you for your comment, You could replace the Chrome polish with alcohol and you can even over reduce the formula with alcohol to be able to spray it, after all the real magic is in the Plaster of Paris. Make sure to wait till the formula completely dries before you engrave.
We don't like to spray due to the fact that spray guns and airbrushes make lots of overspray which is not so good for your lungs if you don't have the right equipment and also they are very hard to clean(time consuming). Good luck and let us know your findings.;)
Best regards
Surge