I wish I could say I was especially optimistic but have some very real doubts as to performance and robustness versus the proper cartridge filter and whether the cost savings will actually be realized.
A typical DC cartridge filter has in excess of 100sq.ft. of filter surface area composed of deep closely spaced pleats. By comparison your filters will likely have somewhere in the 10s of sq.ft. of surface area. The DC filter is typically contained within a steel cage both to protect the filter as well as to help contain the filter material and prevent it from billowing outward (and possibly failing). The actual filter material is also typically quite heavy duty and will yield a long service life before failure and some can be washed a few times, if necessary, to extend their lifespan.
I do not know off hand which which Wynn filter is meant to mate up to the HF DC, but when I visited the Wynn online shop it appears that there are many potentially suitable candidates for $150-200, or thereabouts. When I evaluate a project like this I like to consider the benefit to risk ratio in determining if it is worth considering taking the chance on a, shall we say, "creative" solution. In this case the best possible benefit versus the proper Wynn filter would appear to be a savings on the order of $30-100. However, the risks are many, from catastrophic failure (total loss of investment) to reduced DC performance to greatly shortened filter life expectancy -- to yield real savings your filter would ideally need to equal the performance of a Wynn filter while lasting at least half as long as the equivalent Wynn filter. How confident are you that your filter can meet or exceed those criteria so that you have a reasonable chance to reap the benefits of the cost savings? Lastly, assuming spectacular success on your very first attempt, what value, if any, do you place on the time and labor you will be investing in this project as this adds to the ultimate cost?
In the final analysis, though, only you can answer many of these questions and the degree of risk versus reward you are prepared to accept. In the worst possible outcome you will be out the cost of $118 plus the cost of a new Wynn filter (plus a possible shop cleaning if subject to catastrophic failure in use) plus your time and labor. In the best possible case you are saving perhaps $30-100 it would seem.
Regardless, I wish you all the best on whatever solution you decide upon.
PS -- The dollar figures quoted above are based upon representative samples taken from the Wynn online store. If the required filter must be custom manufactured then the costs/savings quoted above will need to be adjusted accordingly to reflect actual filter cost.