After looking at the ILS RW 12 at HIO, I wonder if DUCKA can be identified inbound once established in the hold using UBG VOR DME and BTG VOR and the switch NAV 1 to the localizer freq to maintain centerline and then have the NAV 2 tuned to BTG to identify Ducka, Couve and Dolla?  If not then you'd need 3 nav radios or start switching one really fast back and forth or have a IFR GPS.

For instance, if you are inbound on the 256 radial from BTG at 4500 ft, you identify DUCKA when the 318 radial centers and shows 29 DME from UBG, then turn to 273 heading for one minute and make a standard teardrop entry by then turning to back to DUCKA.  If its from UBG then its a parallel entry.  Is it legal to identify DUCKA to enter the hold and then tune NAV 1 to the localizer 110.7 in to fly the inbound track of 123 degrees.  Once inbound, BTG needs to stay tuned in to show DUCKA (256 deg rad.) and then Couve (242 deg) and then the Final Approach Fix of Dolla (234 deg) given that the localizer has no DME.  Seems that Nav 1 needs to be switched to the localizer freq otherwise you cannot fly the final approach course.  My interpretation is that Ducka can be identified once for outbound if you are using the holding pattern.