For persistant water ingression problems on larger systems Vacuum dehydration may make sense. But there are other less expensive options. A centrifuge is usually much less expensive to install and usually will take care of persistant water ingression. If operated on a continuous basis a centrifuge will remove free water and any sediment which forms in your system prolonging the system filter changeouts. Centrifuges are likely the most common ofline water removal system for large circulating oil systems because they offer fairly easy use and once set up only require an occasional (weekly) cleaning with no filter elements to replaceto maintain.
Water removal utilizing water absorbing filters is inefficient because these types of filters can only remove free water and some loosly emulsified water. On a chronic problem like you describe the effort of frequent changing of filter elements and the costs of the elements themselves make the long term use of filters a very expensive choics. There are water coalescing filter systems which work by increasing teh size of the water particles as they pass thru the elements until they are large enough to fall out of solution which offer longer filter life and less manpower to operate. Coalescers still only remove free water and do a bit beter at breaking down emulsions than do water absorbing filters but do nothing for disolved water. All that being said vacuum dehydration is the most efficient at removing water as it can remove all three types of water contamination (free water, emulsified water, and disolved water).