Verdict: Unconfirmed.

In a thorough systematic review of interventions for school refusal by [Maynard et al (2015)][1] (also reported in [Maynard et al, 2018][2]), this strategy is indeed mentioned (pg 15):

> ... reducing the young person’s access to items and experiences at
> home which might otherwise positively reinforce the refusal to attend
> school ...

In general, school refusal is treated using standard psychological interventions such as cognitive behavioural therapy (CBT), and possibly medication. Since CBT and the like are "package" therapies - that is, they are customized for each patient from a broad collection of available strategies - determining if the specific strategy in question contributes to treatment effect would require a [component analysis][3]. Given that school refusal is a very niche area with few studies (the above review found 8), it is unsurprising that no such analysis has yet been performed ([Elliott & Place, 2019][4]), let alone one testing the effect of this specific (infrequently used) strategy.

The review also quotes another author:

> "... the search for a definitive behavioural technique or group of
> techniques to suit all cases is inappropriate. … every case is unique
> and will require slightly different emphases in treatment."

For example, if school refusal is primarily associated with anxiety, then a boring home environment will do little to address the underlying issue. Thus in any case, I would not apply this strategy universally.


  [1]: https://doi.org/10.4073/csr.2015.12
  [2]: https://doi.org/10.1177/1049731515598619
  [3]: https://www.studynotesaba.com/glossary/component-analysis/
  [4]: https://doi.org/10.1111/jcpp.12848