Redirect to the IP of a fresh whitelisted Domain after whitelisting
eg: www.adserver.com is at 123.456.789.1
http://www.adserver.com/evilad.txt -> PiHole Website
-> whitelist
redirect to 123.456.789.1/evilad.txt
Are you asking for the whitelist change to be available immediately? If so, the only way to do that is to clear whatever DNS caches lie between the Pi-hole and your device. The Pi-hole's DNS server immediately gets updated, but your device's cache (and sometimes browser cache) are not updated immediately, because they are using the cached response from before you whitelisted the domain. So you need to clear those caches before you're sure to see the changes.
Yeah i know but if i am on a Android or a IPh*** i can't clear the DNS-Cahce and if i could, i was to lazy to open the Terminal emulator, go into the shell and flush the dns 