"Volt meters use a small current to check for continuity "
You could confuse some folks that way. Voltage meters don't check for continuity, they check for voltage. Multimeters, when being used as ohmmeters, check to continuity by applying a small current to the leads. And of course these days almost eveyrone uses a digital multimeter, not a dedicated voltmeter. But considering how many sailors will read at face value...be kind to the newbies.
A Zap Stop can be a good thing, it is really a $5 specialty diode if you know where to order one, and with the usual markets and expenses $25 is not unreasonable for one. BUT. Last time I was on a boat with one installed, both leads had broken off the diode because the owner had simply installed it with electrical tape in the middle of the wire, without any strain relief. It MUST be mounted and secured to prevent that failure.
And even better, there are a number of modern alternator designs with protection built into them, which can be disconnected (i.e. switched over) while operating, without taking any damage. You really need to know what your alternator can take, before bothering with something that can add more failure modes to it.
A 1-wire alternator is a kludge job that will never charge batteries properly, since it can only measure alternator output voltage and it never really monitors battery voltage. Good way to charge and cook a cheap battery on a tractor or a cheap boat. Bad way to treat anything that will cost more than $100.