I hope nobody takes offense at the following statement, but I concluded a long time ago that all the various contrivances for faking ratlines - injection-molded shroud/ratline assemblies, plastic-coated thread ones, flexible plastic ones, Heller-style jigs, "loomalines," etc. - are silly. The Great Ratline Problem, in my opinion, is a hoax perpetrated on the modeling public by kit manufacturers. The truth of the matter is that, on all but the smallest scales, rigging ratlines is no more difficult than plenty of other tasks involved in building a model. It takes a fair amount of time, but not as much as most people seem to think - and probably not significantly more than it takes to use most of the aforementioned gadgets.
Over the centuries modelers have come up with two basic techniques for rigging ratlines with thread. (Wire and photo-etching are other topics.) One - the "authentic clove-hitch" method, generally preferred by people who have some practice - and just about anybody working on a fairly large scale. Two - the "needle-through-the-shroud" method, an eminently respectable and somewhat less time-consuming alternative for less experienced modelers and those working on smaller scales. Here's a recent thread in which we discussed both methods:
http://www.finescale.com/FSM/CS/forums/620138/ShowPost.aspx
Note the way this thread started and ended. The orginal poster started with the assertion that he just couldn't do it. He stuck with it, and within a few days he was describing the process as easy and even relaxing. That's a common experience.
There are, of course, plenty of unfortunate people whose nervous systems, muscular coordination, and close-range eyesight aren't up to such tasks. I would respectfully urge people like that to pick another hobby; this one isn't going to provide the relaxation and satisfaction that hobbies are supposed to provide. My observation, however, has been that the vast majority of modelers who think it's hard to rig ratlines have never tried it - or have given up without giving their fingers a chance to learn how to do it. If you can assemble and paint fifty or sixty miniature gun barrels and carriages, you can rig ratlines.
For a small-scale model of a large ship, like La Flore or the Wappen von Hamburg, I'd recommend starting with the "needle-through-the-shroud" method. I can't see why anybody who's up to the Model Shipways Sultana should have a serious problem rigging the ratlines to scale - i.e., tying the individual knots. She doesn't have many shrouds, so there aren't many knots to be tied, and the kit is on 1/64 scale, so the knots will be about 3/16" apart. My guess is that anybody who gets the rigging on such a model to the point that he/she is ready to think about the ratlines will find the actual rigging of them to be downright easy - a job for an evening or two.
Far more tricky, for me at least, is the rigging of the deadeyes and lanyards. That's likely to prove the toughest part of the rigging on a model like the Sultana. But again, because there aren't a lot of shrouds on the model it won't be nearly as hard, or time-consuming, as it would be on a small-scale model of a big ship.