This URL suggest that blocking /32 host routes in a point-to-multipoint environment is possible using filtering. I've tested it using the correct code but it's not successful.
I just want a sanity check - anyone?
"If you need to block the OSPF /32 routes, you can add the following on all hub and spoke routers:
router ospf <#>
distribute-list prefix-list Block-32 out (block OSPF/32 connected routes)
ip prefix-list Block-32 deny <tunnel-subnet> <mask> ge 32
ip prefix-list Block-32 permit any le 32
â Use Cisco IOS Software Release 12.4(9)T or later instead of 12.4(6)T. This is because we need to have a fix to NHRP so that it
won't be confused by the Cisco IOS OSPF behavior of installing /32 routes for the directly connected routers on the GRE tunnel
interface. Otherwise use the technique above to have OSPF block adding these /32 routes to the routing table if you need to run IOS
code between 12.4(6)T and 12.4(9)T."