Stereo subwoofer cable or interconnect plus Y-cable?

I am the proud owner of two new Rythmik Audio F8 subwoofers, which limit signal inputs to one RCA or mini XLR input on each sub. I have an Oppo BDP-205 connected by interconnects with RCA jacks for 5.1 channel sound to one set of a Parasound P7 preamplifier's multichannel inputs. From the P7, I have connections to a Hint ntegrated amplifier (early version, not the Hint 6) by interconnects with RCA jacks only for the front left and right channels (via the Theater Bypass inputs) and the subwoofer channel. I discovered during setup that one subwoofer input feeds only one subwoofer output on the back panel of the integrated amp. That is hardly surprising, although it had me confused last evening, since only one subwoofer was producing any sound in 5.1 channel playback. My contact at Parasound confirmed that I should be able to solve this problem of routing a single subwoofer output signal from the P7 preamp to both subwoofer inputs on the Hint integrated amp by adding a Y-cable (one female jack with two male output jacks) to the single interconnect from the P7 preamp. I also noticed that Wireworld makes stereo subwoofer cables. Presumably, those involve one male jack on one end and two male jacks on the other end of the cable.
Has anyone here used a Wireworld subwoofer cable in this way (i.e., as connection between preamp and power amp)? This is likely a cheaper solution than buying a single interconnect with RCA jacks and a Y-cable with RCA jacks, and it would eliminate one additional connection in the cable chain in the process. Is there any reason that a subwoofer cable is unsuitable to this application?
Thanks for any helpful suggestions as I evaluate options.