MySQL Database Poisoning: How to recover to a known state quickly If you want to avoid database poisoning (ie want to recover back to a point-in-time quickly) which methodology do you prefer?

Let me define data poisoning. You insert some things in your database which totally messes up the internal structure and interdependencies. I know it means that database design probably also needs to be revisited, but the damage is done. 

The methods I have in mind are


Somehow setup replication in which the slave is passive and is X hours behind. If I have a failure all I have to do is reset the application and point it to the slave as my new master. I suspect that it is possible.
Do a hot backup of MySQL every few hours and when failure is detected restore to a backup from X hours before. This would mean a downtime for the application since I cannot let the current application keep on running. One could use innobackup or percona for quick backup and recovery steps.
Design the application and database specifically so that newly added data gets nuked (or shelved). This means I store all events/states (I guess this is the most difficult and theorotical solution)


If the first option is possible and it also stores all the relay logs (ie what ever happened on Master gets transfered to Slave at the same instant but is applied in a few hours automagically) then it would be a perfect solution. Perhaps one could setup multiple slaves in a setup to recover from both an outage and data poisoning
You can use the pt-slave-delay tool from Percona Toolkit to keep a replica delayed by the amount of time you choose.