Note: This procedure requires editing a game file; creating a backup copy of the file before proceeding is recommended. With a text editor, edit the .xml file in the "save" folder in the game directory. Locate the "ResBonus" entry. It will appear similar to:
Type 10 is the hammer. Type 11 is the lightning bolt Type 12 is the bomb Type 13 is the hourglass Type 14 is the cross Type 15 is the star Type 16 is the shield Type 17 is the mixer
Change the amount to "200" (not the "min amount") and you will always have them ready to use. If you need them again for the same level, exit the game and repeat the steps.