Ultra-light scalars could explain the observed properties of dark matter. These scalars may couple
quadratically to Standard Model fields. From these couplings a scalar gains an effective mass
which shifts according to the local density of matter. This change in mass causes the the amplitude
of the field to shift in the environment of detection experiments. In our work we show that a
cavity-like matter environment around an experiment - such as a vacuum chamber, laboratory
room, or the casing of a satellite - can exponentially suppress the amplitude of scalar oscillations
in its interior. This substantially weakens constraints on scalars with strong couplings to standard
model fields. In light of this fact, we discuss the possibility of using fifth force tests measurements
on bodies orbiting the Earth to access regimes of strong coupling, on account of their minimal
matter environment.