To use the damned thing you need to tap "f" quickly for a long time, which is tiring, frustrating and plainly stupid. I think it's an f-you from the developers.

This guide will tell you how to avoid doing that, provided you play the game on Linux, and you have at least a basic knowledge about the system.

On Linux everything can be solved with a script. -- Albert Einstein

First you have to install xdotool (apt-get install xdotool). What this tool can do is to send fake keyboard or mouse input events or any X Window System event to any window. It's a really nifty tool with more features you'll ever need, just man xdotool if you want to know more. We'll use it to convince the game that the "f" button is pressed repeatedly.

The xdotool can read commands from a file, so the best solution is to create a two-liner script for it (yes, I know it can be done in one line, but I like it this way). The file should contain this:
but with a lot more f's. To do that you can either copy-paste them in the editor, or you can do something like this:
(I call the script "typef", but you can call it whatever you want)

The command tells xdotool to emit "f" ten times per second to the active window, so the above example will work for 1000 seconds (about 16 minutes). It is important to have all f's on a single line, or it won't work.

Finally, make it executable (chmod 755 typef), so you can start it as "./typef", and stop it with Ctrl-C when you're done.

Now you are ready for some serious treasure-hunting.

You need to open a terminal window, and run it, of course. Some important things:

• Only start the script after you equipped the rod, or you won't be able to do it
  
• Don't try to enter an other area while xdotool is running, or the game will crash
  
• If you run the game with wine, you can simply alt-tab to a terminal window to start the script
  
• If you play the Linux port of the game (you shouldn't, because it has visual bugs, and gives no achievements), you need to activate the steam in-game overlay to be able to alt-tab to the terminal window
  
• The deep arrowheads respawn each time you enter an area, so you can collect as many as you want

With the script running you simply need to walk around the camp, and the deep arrowheads will be unearthed as you approach them. You only need to collect 1200 arrowheads (800 for the cobweb duster, and 400 for the magnet), which shouldn’t take much more than 10 minutes. All the other things you'll need to buy later are cheap, and once you have the magnet you'll have all the money you need, because you automatically collect the dropped arrowheads from fallen enemies and destroyed props.