@raymondo, you can also use an exploration to list all the tickers that you want to drop from the database.
From your post, I think that you'll need to define your filter criteria based on the close price below a certain amount, maybe on light volume, and if you have already classified your tickers in different markets/groups or watchlists you can use also that criteria to refine the resulting list (AMEX only).
A) Run the exploration (on all the symbols, 1 recent day).
B) Double check the exploration resulting list of tickers. If everything is as expected go ahead. Otherwise, revise the filter logic until you are satisfied.
C) Once done, click with the right mouse button on the exploration results list: a popup menu will show you a list of menu items:
Select the "Replace watchlist with the results...".
D) Select a destination watchlist: choose one of your empty watchlists (otherwise you'll overwrite the existing content).
E) Then go to the watchlists list and select the one that now contains all the tickers you want to drop. (Here if needed, you can still decide to remove some symbols from the watchlist, using the right mouse click contextual menu choice "Watch List -> Remove selected symbol(s)").
F) Select with the mouse the first symbol in the actual watchlist. Then press the Shift key and also the End key to select ALL the symbols in the watchlist (or use Shift and the Arrow Down key until the end of the watchlist)
G) When all the symbols are selected (highlighted), press the right mouse button to open the contextual menu. From this menu select the "Delete" item.
H) A confirmation dialog will ask you what you want to do. You should select the option to perform the operation on: "Multiple Symbols Selected".
I) A further confirmation dialog (a very wide one... here I posted one for few symbols) will ask you, for the last time, to confirm your choice "Are you sure to delete....".
Select: "Yes, Delete Permanently"