Someone

bind join -|- *!*@* mc:join

proc mc:join {nick uhost hand chan} {
if {![info exists antirepeat]} {
  utimer 15 mc_msgonjoin
  set antirepeat 1
}
}

proc mc_msgonjoin {} {
global antirepeat

 putlog "$antirepeat"
 putlog "testing"

utimer 30 [unset antirepeat]
}