Sweating the days away.  I remember when I first found out about 'toggle auto-use tool' under the action menu (press 'y' default key), then 'control' tab along bottom of action panel, then the '>>' in the middle of the bottom of the action panel, then over three times '>>'.  then there on the lower right is the 'toggle auto-use tool' icon/button.  Setup a keymap to get this icon mapped to (I prefer) a number key such as '0'.
Then when wanting to continously use a tool, equip the tool, press the '0' and away it goes, no clicking.  Aim the tool and go clickless (click to aim) I should say. 
If I had known about auto-use years ago, not 4 years in, my life would be a lot less clicky.  I logged some 300,000 some clicks sweating before wising up to 'toggle auto-use tool'.  Clicks not wasted as I still have A LOT of the sweat looking for better prices in better neighborhoods.  And I have sold about as much as I have left.  (takes some entropia math to understand that, 1/2 of 1 is 1/2, start with 200,000 sweat, sell 100,000, have 100,000 left) 
Now one of the complaints I've seen about 'toggle auto-use tool' is that auto-use makes avatars look like they are controlled by bots.  Botting, being a automated way to play other mmos and usually against those other mmo's rules.  But in entropia 'toggle auto-use tool' is a boon, a clear plus, and saves much sanity from fleeing mice and keypads.  And auto-use is within the rules of entropia as 'toggle auto-use tool' is included in the action panel list. 
The inclusion of auto-use goes a long way towards making entropia gaming A LOT more fun and less demanding.  There are a few problems still as it applies to sweating but on the whole 'toggle auto-use tool' is a keymap tool to use that I cannot live without.  Hope you have found auto-use and good luck.