Humidipaks are not intended for dehumidification in high-humidity environments. Though they are a two-way humidification system, which does allow them to both absorb and release moisture, if your instrument is already over-humidified, the packs aren’t intended to remove large amounts of moisture from the instrument.
Humidipaks are designed to maintain a humidity range between 45%-55%, but they can only do this when the case and guitar have been pre-conditioned to those levels first. If the environment already has high relative humidity, Humidipaks won't be able to lower the humidity to that optimal level. For optimal performance, please pre-condition your instrument/case to 45%-50% before using Humidipaks. This will allow the Humidipaks to maintain the 45%-55% range by releasing and absorbing small amounts of moisture at a time.