The best way I have found for using the Shellspen ceramic shell system, and pour cups. Is to not put your cup on the end of your sprue. Instead coat your sculpture and sprue system completely, dipping the entire piece into the slurry. Leaving a stub where your cup will be. Also at the same time your start slurry coating, slurry coat a circular dixie cup, on the outside only. (Dixie cups, like the ones your find with those water bottle systems everywhere, they also make a larger size Dixie cup which works great!) When you've completed all your slurry coats, and your ready to de-wax, simply take a coarse blade hacksaw, and/or a small grinder, and grind off the end the sprue stub, (to where the wax is exposed), where your pour cup will go. Then take your Dixie cup, remove the paper cup from the inside, ( the side you did'nt coat ), and match up the size of the sprue it will be attached to. And cut, or grind off the end of the cup, ( now in ceramic shell ). Then de-wax the the scupture and the cup, unattached. After de-waxing, set up your sculpture in your pre-heat
( for casting ), and attach the cup to the sprue opening by using the AP Green # 36 Refractory Cement, ( included in your Shellspen Kit ), like a mortar or mud, then let the pre-heat heat it, and harden the attached cup before pouring your molten metal. You can take a torch, and fast heat the mortar or mud, ( it will blister a bit, and you can fill in any holes from the blistering with more mortar or mud ).

This process should save you time, and make it easier to coat your piece in the small confines of a 5 gallon slurry container or similar size.