That is of course pretty much what the "Glansie" device amounts to, and is very appropriate to an extremely narrow foreskin opening, of the degree where it is difficult or impossible to visualise the glans at all.
I tend not to advise the "Glansie" as I feel it is
only useful in this circumstance, and loses its purpose once you can fit a finger or similar-sized dilator. When you have the Glansie - or the pliers - widely open, they are bearing on a quite narrow area of the circumference of the foreskin and it would be too easy to cause an injury which of course, then delays the whole process.
Certainly the use of "snubs" is an excellent idea. I happen to have quite a collection of these of different sizes, including the small ones which would be suitable for this purpose here. They are used to protect the "pointy" parts of medical instruments during handling and sterilisation, and are perfectly shaped with a smooth rounded end but this is not going to be a practical source for most people. The same item however is (or used to be when home construction of projects still existed) available in electronics shops as a cover for the lever of small toggle switches.
Failing this, small lengths cut from the insulation of electric cables, or thin plastic tubing such as aquarium air tube, rounded by holding and slowly twirling the end
near the flame on a gas stove, can be used. As stretching proceeds, you can place a larger snub over a smaller one to apply more even pressure.
In practice, the pliers are going to do pretty much the same job as the Glansie. The Glansie is easier to use as the tips open on squeezing the handles together (like circlip pliers) and the more expensive version has a ratchet device to hold the pressure (though a Post Office rubber band would be almost as useful). Neither however is practical to leave in place during other activity (except keyboarding

) - you have to sit in a private place while the device is used.
If using pliers, of course clean them thoroughly beforehand and go over them with alcohol. The nickel plating on some pliers can cause a reaction, which
is another reason to use snubs.