I'm not sure, I haven't tried that. You would have to get a snug fitting connection to the intake in order for it to stay on as you work cleaning the substrate. But sure, you can always try out some homemade combinations to see what works for you.
I just know that with the HOT Magnum you can remove the intake tube and fit their siphon into that port. The connector is already on the tubing and you secure it down tightly with the clip that is already on the port. Mine all came together, I think they call it the Pro Series kit or something like that. Or the Magnum siphon is available by itself if you already have a HOT Magnum. These filters are a little on the expensive side at the LFS (the filter by itself was $89.00 at my local Petsmart store). I usually can find them at a lower price through one of the mail order/online catalogs, but I haven't priced them lately so I'm not certain. They may have gone up in price.
I just know that with the HOT Magnum you can remove the intake tube and fit their siphon into that port. The connector is already on the tubing and you secure it down tightly with the clip that is already on the port. Mine all came together, I think they call it the Pro Series kit or something like that. Or the Magnum siphon is available by itself if you already have a HOT Magnum. These filters are a little on the expensive side at the LFS (the filter by itself was $89.00 at my local Petsmart store). I usually can find them at a lower price through one of the mail order/online catalogs, but I haven't priced them lately so I'm not certain. They may have gone up in price.