I had not heard of Dike.

It got 6 good reviews on Amazon.

http://www.amazon.com/Dike-Temporary-Radiator-Stop-Leak/dp/B002HIB3GI

Homepage at Conklin

http://goo.gl/QpNSO

Sample quote

Key Benefits

Stops leaks in radiator in seconds
Seals internal leaks, preventing antifreeze and water from seeping into the engine
Helps gaskets seal better
Will not block small passages in the coolant system
Works with all antifreezes
Note: If the cooling system is filtered, the filter should be removed or bypassed when using Dike.

Less than 4 gallon systems

For best performance:

First flush radiator with Radiator Flush
Premix 1 pint of Dike to a minimum of 1 gallon water/antifreeze blend, add to radiator
Fill radiator with water/antifreeze blend to manufacture specifications