Humpty is correct as always 
First you might want to make a backup of the reg key then remove the Washer entries using a reg fix to save you having to manually edit the registry.
Goto Start Menu > Run > Type (or copy and paste) this into the run box
regedit /e C:\Backup.reg "HKEY_CLASSES_ROOT\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}"
Then Press OK, this will create a backup file on C:\Drive named Backup.reg
(To add the information back anytime you can just double click that file or right click and choose Merge, to view the contents just right click and choose Edit)
Next Remove the Washer Key
Open Notepad (Start Menu > Run > Type notepad and Press OK)
Copy and Paste the contents of the code box into Notepad making REGEDIT4 the top line.
REGEDIT4
[-HKEY_CLASSES_ROOT\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\Shell\Washer]
Goto File on the top bar and choose Save As, Change the Save As Type to All Files, Name it Fix.reg then save it to your desktop
Double click Fix.reg (or right click and choose Merge) and it will ask if you want to merge the contents into the registry, choose Yes and the specified reg entry will be removed.
No more Right click option for Window Washer
Andy
