Incredibly low water pressure through ancient galvanized pipes to exterior spigots - possible to "pipe clean"?
Hi folks, I have a 120 year old craftsman house in Seattle, and over the last few years I've noticed the water pressure to the exterior hose spigots has dropped *dramatically* - as in, basically a dribble. I've had the city out twice to check pressure to the house, and it's just fine, so I know the issue is inside somewhere. Water pressure inside the house is also fine - maybe not high pressure, but plenty for faucets, showers, etc.
The current working theory is that the galvanized mainlines in the house that feed the spigots may have gotten encrusted/rusted inside, reducing flow. My question is if there is a reasonably safe way I could use something like a scrubbing "pipe cleaner" to loosen much of the debris on the inside of the pipe? I'd imagine removing the exterior hose bib, running the cleaning dodad inside the pipe, and then turning on the house supply to try and blow out some debris.
I understand there may be a risk of breaking off too much of the interior crud, so I don't want to be too aggressive. But I am hoping to find some middle path to get this working a bit better for the next 5 years or so (am in an up zoned area, and it's likely these homes become apartments in the not too distant future). Really appreciate any tips or hints or "don't do it!" sorts of warnings, with thanks!