Varig didn't have the early water-injected JT3C-engined 707-120, which was confined to US operators (it was used on B-52s and KC-135 tankers previously). Varig were early 707 operators in 1960, but with the Rolls-Royce Conway engine; they had just a couple of these (ordered three, but one was lost before the final one was delivered), then they bought a few Convair 990s (GE engines), then merged with Panair and got two DC8-30s from them (JT4A engines), then got their first 707-320C in 1965, which they then standardised on, and sold off their decidedly mixed, both airframe and engines, earlier fleet. Their Rolls-engined first 707s had maintained an element of commonality with the Rolls Avon-engined Caravelles which they bought at the same time.
JT3C water-injection was a nuisance operationally, it added a considerable weight, both for plumbing and water, although it only operated for the first couple of minutes from brake release so you didn't normally carry the water with you, it was complex and unreliable, and created extra noise and smoke. You needed anyway to plan for the water injection to fail at V1, which was by NO means unknown.
Pratt had another go with it on some early 747 engines (those with a W suffix), more as a Band-Aid to the poor performance of the first JT9Ds, but this apparently had even worse reliability and was soon dispensed with.