Procedure Increase By % Using Criteria?

I am trying to increase the price of an product by a user entered % for items with Dishwasher in the itemdesc.

Below is the procedure I have which doesn't appear to show any errors in the SQL Developer.

CREATE OR REPLACE PROCEDURE AdjustPrice(
pItemDesc IN ITEM.ItemDesc%TYPE,
pPercent IN NUMBER)
IS
BEGIN
UPDATE Item
SET ItemPrice = ItemPrice + ItemPrice * pPercent / 100
WHERE ItemDesc = pItemDesc;
END;

This is my run script:

BEGIN
AdjustPrice ('%Dishwasher%',10);
END;

I think the problem is with the way I have done the run script to filter to items with Dishwasher in the description. I tried LIKE an that didn't work either.