Hello Manuel.
The dummy route that you indicated above will not work for two reasons. First the route must be in the format:
ip route network-address subnet-mask Next-Hop-address/interface track1
I believe you meant the following:
ip route 0.0.0.0 0.0.0.0 192.168.23.3 track 1
If this is the case, then this would not work either, because 0.0.0.0 0.0.0.0 is a legitimate route and would affect your routing. You must use a network address that does not exist in your topology. Also, it is always safer to use the null0 interface as the next hop interface so no accidental unintentional routing takes place. Also, the null0 interface will guarantee that the route will be entered into the routing table.
I hope this has been helpful!
Laz