You can also replace ads and banners with a few of SafeSquid's built-in templates, instead of creating an htlm file to replace them.

 Try using these built-in templates -

1. checkeredgif - appears as a small grey dot in the upper left corner
2. uparrow - appears as a small uparrow in the upper left corner
3. downarrow -  appears as a small downarrow in the upper left corner

To use these templates, just replace the 'Template' option in the rule under URL redirecting, e.g. -

http://safesquid.cfg/template/checkeredgif